Role-Playing Game Design Theory
I really need to stop reading discussions of role-playing game design theory. While there are occasional gems, there are too god damn many architecture astronauts dominating the online discussion. You get posts and discussions using a whole new language without bothering to define the definitions, or worse, pointing to a 300 post message thread as an explanation. You get pronouncements about how braindamaged everyone playing badwrongfun[1] games are. You get the idea of role-playing so generalized that the resulting game lacks roles that the participants play.

Ultimately if you don't understand why Dungeons & Dragons is popular, I find it hard to take you seriously when you tell me how you're going to make role-playing better. (Free hints: If you think it's all marketing and first mover status, you lose. If you think it's because fans of D&D are somehow stupid or inferior to you, you lose.)

[1] badwrongfun: Playing "the wrong way", but having fun anyway. You might be playing the wrong way by going against the expectations of the game ("You can't run a hack-and-slash game using Vampire; you're missing the entire point!") or the expectations of gamers who have decided they are more evolved beings ("It's not possible to properly role-play in Dungeons & Dragons."). Primarily used humorously to show that the speaker doesn't care that it's "wrong" since it's fun, or that the speaker feels a slight bit of guilt for enjoying something they feel they shouldn't.

(Edit 2007-11-04: "message thread and an explanation" changed to "message thread as an explanation".)