You have to think that one reason people are so pessimistic these days is that when we were growing up, every third movie involved an apocalypse ... via zombies, robots, monkeys or natural disaster. It can be kind of a downer, but if you want to make yourself feel better, all you need to do is remember that almost none of the apocalyptic scenarios actually work.
What do we mean? Well ...
5In the Terminator Series, the Machines Have No One to Build Their Army
In the Terminator series, the American government ill-advisedly relinquishes control of their nuclear defense system to an unfeeling artificial intelligence programmed only to kill. It proceeds to do so indiscriminately, and mankind is reduced to a few scattered rebels fending off hordes of Austrian robots.
"Sir, may I ask why it's giggling?"
So, What's the Problem?
Who or what is building all those Schwarzeneggers?
At the time when Skynet initially nukes the world, it's still just a computer program drifting around the Internet. Sure, it has access to nuclear launch codes, but not to more delicate equipment like opposable thumbs. Even if we assume that, in the world of the film, Skynet is able to hack into and usurp control of every factory and power plant through the Internet, it's still inheriting a world of machines designed to be operated by humans. That means valves need to be turned, buttons need to be pressed and levers need to be pulled. And just in case you're assuming that Terminator takes place in some kind of post-valve world, these scenes from Terminator Salvation would seem to suggest otherwise:
"Wait, I'm not here to kill you. I just need you to show me how these valves work."
"We've got to get away from these valves. If they find us, they'll make us turn them."
If you're thinking that Skynet probably just employs a division of Terminators to operate its factories, you're missing the point -- the computer didn't have access to Terminators back when it killed off all the humans. In fact, the most sophisticated robot that Skynet had access to at the time, the T-1, was a goofy-looking tank with Gatling guns instead of hands that could barely fit through a doorway, let alone turn a valve.
It can play the guitar surprisingly well, though.
It doesn't really matter how smart the computer is -- it can't recommission a car factory, for example, to start churning out Terminators. And even if it could, how is it going to mine the ore, refine the metal and drive it in trucks to those factories? You know, all that stuff that still has to be done by human beings with hands?
In reality, after it nuked everybody, Skynet would probably be left with very little to do in the few days it had to live before something important broke somewhere.
Turns out that beating it was as simple as running Skyrim on its primitive graphics card.