...or more to the point, intelligent enemies unbound by human reaction time, common grade school intellect, and the requisite hand-eye-coordination of rival human opponents in multiplayer games.
> requisite hand-eye-coordination of rival human opponents
it's totally possible to force an AI enemy to "play" through a harness that simulates human reaction time, limits in human visual processing (a human can't perfectly focus on all the screen at once -- check out eye-tracking data taken on people who are playing an FPS!), and the latency/error that happens when a human uses a mouse to aim in a game.
The whole point of AI enemies isn't to expose them to all the game's state and let them input commands with zero latency -- that's not an AI opponent, that's just a cheat engine. It's only fun if the AI has no more information from the game than a human player would have and can control the game with no better control authority than a human can.
We've already got opponents unbound by human reaction and with abilities far better than normal humans. They're basically a mainstay of the fighting game genre:
http://tvtropes.org/pmwiki/pmwiki.php/Main/PerfectPlayAI
And they're not that fun to fight, because they're too 'good'.