There's a two-fold reason why so much venom is spat at WoW, from what i've seen of the VG crowd at least. 1. The initial launch was primarily PVP, and cartoony, so the vast majority of the players were believed to be kids (or at least acted like it) and 2. The game was in easy mode. Short of the raiding, there wasnt any challenge to the game (for me at least), and was ultimately very boring.
Not bashing the game, as I actually enjoyed the hunter class for as long as i played, it was the game in general that just couldnt hold my attention.