haha there's like sooo many reasons, besides people don't HATE people who play WoW, its more that they hate WoW, but here are just a few reasons to dislike WoW:
1a) Both graphically and gameplay wise (definately at the start missions) WoW is inferior to most other MMO's 1b) This is only more annoying because so many people play it purely because it has been around for so long, their friends play it (and won't give up because they have high lvl characters or virtual "friends" who play it) so they play it too, and so the cycle continues, 2)It sucks people in, and slowly but surely errodes their life outside WoW, i didn't believe it until one of my friends, who at GCSE (high/comprehensive school lvl grades) got mostly A's, has now totally failed all his AS levels (and been forced out of college), primarily because now he plays WoW all night, every night. 3) As my friend as a perfect example, people who play WoW excessivly tend to stop going out, or to social occassions, even after specific invitation, preferring instead to play WoW. 4) WoW i think acts as a "gateway drug" for other similar computer based activities, such as text roleplaying online, excessive porn browsing, eating and drinking energy drinks constantly at the computer, all to excess and all reducing real life socialisation time. 6) constantly playing at ones computer leads to being overwieght and unhealthy, 7) eventually lacking social abilities to interact with non-WoW players (as differences in speaking (leeeroy jenkins etc) and having less in common)
Btw i'm not saying that this definately happens with WoW players, but from personal experience and what i've seen and heard else where is quite typical