The only thing that really annoyed me was the dwindling level of player customization. Select your class select your build, you're done! Most of the choice was taken from the player.
Yeah when they started killing the really neat and unique builds you could off is when I quit the game. The class homogenization just became more and more annoying. Cataclysm felt like a really weak expansion too and I think at that point I was just burnt out and needed more time for friends/family.