From what I've seen, the TF2 community is just as bad as the MW2 guys are, since they get incredibly butthurt over the smallest changes in the game.
Well, yes. Bascially, every update to the game, no matter how small, is simultaneously the best and worst update in the history of video games. Additionally, hats are
very serious business, and you
will get called a noob for using Natascha, Force-a-Nature, or Demoknight (or really, any form of Demoman at all, though that's died down a bit since the game's beginnings), no matter how many different types of kills you get with them.
But, to elaborate on what Warp said, once you buy TF2 (and it's already pretty cheap), it pays for itself, bub. You now have a lifetime free subscription to awesome maps and weapons, and the occasional new gamemode.