I blame the brown-gray stylings of "next generation" game design. Games are turning into dystopian worlds you don't want to be in instead of fun things you want to get back to. It seems to be less prevalent with downloadable games which is why most of my money goes to those now. Also retail games love to overcomplicate crap (why the hell does every button on a PS2-like controller have to be mapped to something in a game about running around and shooting anything that moves? EDF has 3 buttons, 4 on some weapons and that's it and the game is ####ing awesome!) which downloadable games can't do as much because they have only limited disk space to stuff features into. Needless, "epic" stories in games that are really just about stabbing stuff in the face with a chainsaw, gigantic efforts put into making every part of a level as detailled as possible but finding that there's no money to make a lot of game that way so everything gets copy-pasted, games that have pretty much one enemy type because they are meant to introduce you to multiplayer gameplay in the campaign so all you fight is basically bots and then a multiplayer mode that requires unlocks to get anywhere...
In the end games are just toys but now they're toys that take themselves WAY too serious and want to be high art (while still being about stabbing things in the face with a chainsaw...), completely forgetting the point of their own existence. I hear the comic book industry tried the same thing [http://gameoverthinker.blogspot.com/2008/08/episode-eleven-can-it-happen-to-us.html], turning basically into one big collection of injokes and fanwankery.
Me, I've been playing Onslaught lately, an FPS that could be called generic if a generic FPS these days wasn't mostly about small numbers of enemies and epic stories and graphics and whatnot. These days an FPS that's simply about shooting anything that glows green with a story that pretty much amounts to a back-of-the-CD-booklet paragraph stands out as uncommon.