There are a few reasons people hate the 360 on gaming forums:
1. It has been surprisingly successful for something that was picked to fail from the start.
2. Sony fans hate it because it brought them back down to earth. Now because of the 360 most PS3 fans see 2nd place this gen as a victory.
3. Nintendo fans that seem almost upset that the 360 would dare try to get 1st place back for this gen.
4. PC fans who feel it isn't right that console fans get to play the same games as them. Therefore they downplay the games by saying their inferior because of no KB/M support or the grafiks sux compared to teh wata kewled SLI quad core setup I have running Crysis on max settings at 1440p. :p
5. The people that had 3 PS1's, 4 PS2's but yet complain about the TRL (Three Red Lights) or RRoD (Red Ring of Death, although it's not a full ring).
6. The people that hate how rich Bill Gates is and don't realize he doesn't run Microsoft anymore or that he donates a lot of his money to charity.
7. People that want to feel better about their purchase and/or couldn't afford a 360.
8. The people that do it just because everyone else does.
Love the product, not the company. They love your money, not you.
-TheRealMafoo
