When MMO game developers see the fat money World of Warcraft brings to Blizzard, they become all slobbery and start to crave their slice of pie. Then, they forsake all of the originality and engage copy&paste buttons.

In the MMO community there is nothing as hated, but constantly asked for as "nerfs". Story is always the same - player class, ability or a game feature becomes perceived as overpowered and needs to be severely weakened.