That's not what it means when it comes to game design though. If the enemies are told "go here, do this", that's script. If they're told "FIND COVER AND KILL THIS GUY" and do the rest themselves that's code. And no, today's AI doesn't have to be told that. At all. This hasn't been necessary for a while and with the class setup of modern uber eloquent devkits it's easy as hell to pull off, which is why it's not that uncommon. If you have to manually tell every character what to do, you're making way more work for yourself than you have to as a programmer. Calling it "random AI" is an absolute misnomer and not even how that works. It runs an AI routine that relies on random number based class selection combined with analysis of the battlefield and some other such nonsense which yields an enemy that gives the illusion of thought because it's intelligently unpredictable and reacts to parameters in unique and different ways each time. As opposed to "run right" or "walk towards player". Which is the whole basis of artificial intelligence. And, yes, a more random AI is, by it's very nature, a better AI. Because intelligence demands randomness. If you can predict the outcome without forcing it, it's not an AI, technically speaking.
....I think it's quite possible. There are things such as Wolfram Alpha and even Google that do this. (It doesn't specifically need to be able to understand spoken language, rather you can type anything you want, and it should be able to answer something that is relevant. That's good AI.) It's not impossible, it just hasn't been done before because the money that could be spent on developing it has been spent on advertisement and marketing. (There's a guy who has written an AI that develops games, nothing is impossible)
I agree with your last paragraph.
Mind if I ask how far along you are on your programming degree?