Put it out of its misery.
INTRODUCTION:
Yes, Virginia, plot holes do matter.
As a kid who liked sci-fi movies, I often had to deal with the following scenario:
YOUNG SHORTY: That thing that just happened didn't make any sense at all!
OTHER VIEWER: Ha ha, listen to this guy, pointing out plot holes in a sci-fi movie!
And I lacked the confidence and rational/rhetorical ammunition to respond at the time, so let me just speak on my own past behalf here: The fact that a movie qualifies as "science fiction" does not absolve it from all responsibility to make sense—quite the contrary, you could even argue. The best science fiction does make sense, and the reaction (which you often see in crappy New Yorker film reviews) that, "Hey, there are robots in this movie, it's ridiculous right off the bat and therefore impossible to judge," is, from where I'm standing, pretty careless at best, and very possibly smug, stupid, and simple-minded, as well.
A movie can start with certain axioms—like, "Jedi have superhuman abilities and can essentially see things before they happen," in which case, O.K., it's totally legitimate to have a Jedi flying at outrageously high speeds and not crashing and dying in the first two seconds. Young Anakin Skywalker, I believe that you could handle this fucking 20-minute insufferably boring but incredibly dangerous high-speed pod race. I can accept that. But then it has to be consistent. If Superman has to strain to catch an ICBM, I'm going to raise my eyebrows when he flies around the earth at about 100 orbits/second and reverses the direction of time—or if he has to work real hard to slow the fall of an airplane, I'm going to be confused when he can fly a whole island into outer space (particularly when it's half made out of Kryptonite*). Why will I react that way? Because the disparity isn't there to be cute, and it certainly doesn't make sense within the established reality of this fictional universe: it's clearly just convenient to the filmmakers and in effect expresses a contempt for the subject matter—which, if you think about it hard enough, ends up just throwing in your face that the movie industry is a business and this movie is a product and you are a consumer, which is hardly what you want on your mind when you're watching something that's supposed to be fun.
Another, related example: Unless we're to assume that James Bond is just incredibly lucky above all else, how is he weaving through busy city traffic at like 100 m.p.h. while shooting at people over his shoulder? Even if his reaction time is far shorter than a normal human being, unless it's established that he is a Jedi Knight, this just fucking doesn't make sense. Or how does Jason Bourne, unless his midichlorian count is much higher than they told us, know which apartments to cut through in a city he doesn't know in order to leap out of a window and catch up with somebody he's pursuing whom he hasn't even caught sight of in about five minutes? I'll accept that he's an incredibly well-trained, nearly supernatural bad-ass, but does he also have ESP? Does he have maps of every city programmed into his brain? Did he throw a little spider-shaped tracking device onto the bad guy like in the old Spider-Man comics (cartoons?) and we just didn't notice?
And even there—I'm willing to suspend disbelief and figure, "O.K., it's just cartoonish action," but the whole point is that there are different levels of realism: I can enjoy something like that if it's consistent, but if we're meant to treat a movie as the slightest bit realistic and not as a big Looney Tunes adventure, then you've got to make some effort to make the damned thing make sense.

Ripley has very strong arms.
ON TO TERMINATOR SALVATION
The first half of this movie is fine. A little silly, sure, but whatever: I'm watching it, I'm thinking, "Fine. This is reasonably entertaining. Let's do this thing."
The second half of the movie is ludicrous—just nonsense.
I'm tempted to watch the movie again, taking notes, in order to make a really exhaustive list of all the shit that doesn't make any sense, but I am not willing to watch the movie again, even in order to take it down. Near the end of the movie, I was literally looking up at the ceiling of the theater, trying to see through the shadows and thinking, "Wait a minute...does this space have like incredibly high ceilings, or is it just really dark up there?" There are two sins in an action movie that I cannot forgive. The worst is being just plain boring;† a close second is being so meaningless that you can't engage with it anymore, at which point it comes back around to being boring,‡ and that's what Terminator Salvation does.
So without any pretense of its being complete, and in no particular order, here is a more or less off-the-top-of-my-head list of things about Terminator Salvation that didn't make any sense. I'd say SPOILER ALERT, but come on: you don't really want to go see this shit.
- Why are there only two terminators guarding Skynet?
- Why does that terminator keep picking John Connor up and throwing him instead of, say, tearing out his heart (as in the beginning of Terminator) or, I don't know, strangling him? Even punching him directly in the face with a metal hand would probably be a good move.
- Why did Skynet give Wright a heart? I know it's to make him more realistic and convincing to human beings, but the T-800 isn't off the assembly line yet, and it's not like in the other movies you see them testing for heartbeats. Why not just send in a regular terminator and have it act really nice? Was the heartbeat really all that made the difference?
- More importantly, why did Skynet give Wright free will? Maybe it doesn't trust a programmed personality to be convincing enough to human beings?
- O.K., then if Wright has total free will and Skynet has no control over him at all, how did Skynet know things would go the way they went? How did Skynet know, in other words, that Wright would lead Connor back to those two terminators?
- But if Skynet does have some control, why does it just let Wright walk out of its office§ to foil its plan? Couldn't it, say, just shut him down? Oh, I know, he scratches something off the back of his skull, and that somehow means he's gotten rid of the Skynet part of him. Whatever.
- Why does Skynet's simulated face reveal a red-eyed robot face behind it every time it morphs? IT'S A FUCKING COMPUTER IMAGE. It's not like the robot skull is there somehow and we're catching glimpses of it: that would have to be programmed in just like the rest of it.
- How does Skynet know that Kyle Reese is John Connor's father? Yeah, we know, and John Connor knows...but how does Skynet know? Did it just see the other movies?
- If those motorcycle robots were so good at dodging falling wreckage, how come John Connor is able to knock one out by pulling a string across the street? No, wait, I know the answer to that one: because they got more money for product placement by having him ride one, and they couldn't pull that off unless he captured one.
- How did that little mute girl know what the remote control did?
- How come the grey-haired woman is on John Connor's helicopter as if she's an important character?
- Even ignoring the fact that Sony is still alive and kicking, making Skynet-confounding devices for the resistance (product placement, ARRRGH), why is Skynet helpfully equipped with access panels for human beings? Do terminators actually have to punch in codes to open doors in their own headquarters, when they're communicating the-robot-equivalent-of-telepathically all the time? I guess the idea is maybe that Skynet's headquarters were originally built by humans...but then, what, Skynet didn't make any modifications?
- People are always flying away from nuclear explosions, aren't they? If you're in a rocket ship (as in Aliens), then O.K., I don't know how fast your rocket ship can go. But I'm sorry, can a helicopter really fly faster than a thermonuclear blast?
- So, O.K., Skynet sends in a terminator to draw John Connor into its lair, but the terminator decides to help him instead, and then it turns out all right. That's the plot?!
I'm sure there's more, but that's all I've got for now. My overall complaint is that the things that happen seem dictated by a need to justify action rather than adhering to any integrity of story. You get the feeling that the people who made this movie don't care whether it makes any sense—and you expect that of the "suits" at the studio, but you don't want it to be true of the screenwriters.

Wait a minute, guys...is this thing even real?
AND ANOTHER THING, REAL FAST:
A somewhat contrarian assessment of the series.
Terminator is a great movie: simple, original, internally consistent, narratively straightforward, conceptually pure, entertaining, and scary. The terminator is a robot that exists to do only one thing, and when it sees Sarah Connor, it shoots at her immediately and without hesitation, and if it doesn't have a gun, it runs after her, and if you hit it with a truck and mess up its leg, it limps after her, and if you blow it to pieces, it drags itself after her: "it absolutely will not stop, ever, until you are dead." Period. (Also...so '80s. Gotta love it.)
Terminator 2 is packed with exciting action and amazing special effects, but the story is a mess (especially by comparison to the original), and the conceptual purity is all fucked up. Also, there too many long, boring, practically unwatchable stretches; there are too many embarrassingly stupid moments (e.g., "I know now why you cry," "You don't know what it's like to really create something," and all the pretentious highway-at-night narration); and there are too many scenes in which, e.g., the T-1000 could just run up to John Connor at 40 m.p.h. or whatever and kill him but instead walks toward him menacingly. Why? Because
in the original Terminator the robot exists only to kill Sarah Connor, whereas in the sequel the robot exists only to show off the movie's special-effects budget. And let's be honest: that liquid-metal concept, cool though it
looks, just doesn't make a goddamned lick of sense. [SPECIAL AWESOME BONUS FEATURE:
David Foster Wallace on T2! Read it. For real. Much, much better than anything I say here.]
Terminator 3 is not as bad as everybody said it was. I admire that it's got a different feel from the others. I like that the bad-guy terminator is a sexy woman. I like that Skynet isn't a single computer but rather an Internet entity (as in Orson Scott Card's Xenocide, as I recall). But most of all I'm immensely gratified by the ending: the idea that you can't in fact change history by time traveling makes a hell of a lot of sense and is a return to the basic conceptual purity of the first movie. While in the second of course we're relieved that apocalypse has been averted, it leaves you having to ask..."Now, if there's no nuclear war and no Skynet, and if therefore no terminator gets sent back in time to kill Sarah Connor (and probably no time machine gets built, since it's Skynet's superhuman artificial intelligence that makes that shit possible), then Kyle Reese surely isn't going back either, in which case...huh, where did John Connor come from?" T3 says, "No, you can't rewrite history. Skynet always gets built and always destroys most of human civilization; John Connor always beats Skynet; Skynet always sends robots back in time in a last-ditch effort to stop him—this is just the way it goes." For that alone I give the movie a begrudging thumbs-up. (But the "I...AM...A...MACHINE" scene is real bad.)
And Terminator Salvation? Terminator Salvation is some 13-year-old's fan fiction that accidentally got made into a major motion picture. What do the kids say nowadays? FAIL.

Now that's a terminator.
CONCLUSION/ADDENDUM
I already said this, but it's not fair to leave it buried in brackets: Read David Foster Wallace's
essay about the
Terminator movies. Read David Foster Wallace's
essay about the
Terminator movies. Read David Foster Wallace's
essay about the
Terminator movies. Read David Foster Wallace's
essay about the
Terminator movies.
I just think you should read it.
* Is it mind over matter for Superman—just a question of whether he really makes an effort, whether he cares enough? When Kryptonite cripples him, is he just being lazy?
† This isn't a great example, but the pod race in The Phantom Menace comes to mind.
‡ Again, I can't think of a great example (except for the new
Terminator movie itself), but the climactic train scene in
Back to the Future Part III comes to mind...see upcoming
BTTF3 post, part 3 in an approximately 3-part series (
q.
v.).
§ And why does Skynet have an office?