Anyone who has not been under a gaming rock recently knows that games featuring light or non-existent AI, but many simultaneous human players have gained a rather large following. Games like World of Warcraft replace game AI with an extraordinary number of humans (ranging, of course, from terrible to astonishing in their skill level). I am happy for those that enjoy these games and their accompanying socialization. However, as a computer scientist (even if an "amateur" in the sense of not having a PhD to my name) I consider it a failure on behalf of the discipline.
Few games have any true level of intelligence. Most are based on overwhelming the user (i.e. first person shooters where each AI nemesis is cannon fodder--but there is so much cannon fodder one can hardly keep up) or "cheating" (see any EA Sports Game; Jerry Rice becomes Mr. Butterfingers when the 4th Quarter grows too close to a finish; Ryan Leaf and his ilk become the greatest thing in the world. In short: balance simply vanishes), or "peeking" (the computer receiving more data about the user's tactical choices than is possible in reverse). True, these techniques make the game hard, but they lack the fulfillment of beating an opponent who is truly the player's peer rather than some half-omnipotent, half-omniscient being.
Don't be fooled: I am not saying that good AI is easy. Much the opposite. It is, perhaps, the single hardest piece of game development. Graphics, at this point, are not the hard part. In fact, the biggest drawbacks aren't related to programming at all, but rather waiting for the available hardware to catch up to the software's capabilities. Perfect AI is simply not possible right now. "Good enough" AI usually is, but would require substantial effort to put together and why spend the effort? After all, we can simply boast about our ridiculous polygon counts and cool endorsements, right?
MMORPGs simply punt on the issue. Yes, there are benefits to this style that cannot be achieved. The most prominent (and, perhaps, the only) one being socialization. Unless computers could actually pass themselves off as human, this part of the enjoyment is simply not replaceable. But let's be honest: to rival players, the world is so big that the number of people they truly socialize with is fairly small. As a rule, most humans playing are still little better than AI cannon fodder to the small band of friends playing. I rather wish they wouldn't pass off the problem, though. There are methods that are truly promising in games. Rather than encoding a handful of basic patterns, neural networks and machine learning offer some interesting possibilities.
Who knows? Maybe some day I'll start up an Indie game studio with a dedication to AI. I doubt it though. Alas! It is more likely that this will remain the way of it for some time.