Don't get me wrong i find World of Warcraft a great and interesting game with lots of things to do...
But id say the beggining is just to slow... too many 'fetch' quests... i found myself going to the same places over and over again doing these annoying fetch quests.
I found the smithing, socket, gem system a little unfriendly to new-begginers, and even if i tried to ask others how to do certain things, i would be surrounded with rage from deuchebags saying "Ugh i hate newbies, they need to learn how to play the game by themselfs", wich i find arrogant considering i bet these people had difficulties in the beggining and asked for help has well...
Another thing is that i love to explore... but you need to walk a lot... like there is no end and that you can never reach you're destination... mounts balanced things out, wich i LOVED.... till flying mounts came... i love flying mounts, but they shouldn't be usable on azeroth... just sayin...
People are really arrogant and assholish with you, if you're not a women... ive seen real deuchebags turning pussycats within the presence of a girl (man playing has a women character basicly, but let's keep that a secret).
Spammers, screamers/ragers and gold farmers.... basicly this: "GIMME ME GOLD PLZ! GIMME GOLD PLZ!!!!"... i belive you understand the rest.
And the last reason i stopped playing WoW is even though i loved teh diversity of races (Loved trolls, taurens, a little of draenei and loved dwarfs.... with the new game i loved goblins and the werewolfs), i find that it costs too much money, in accordance of time i spent playing.... for each month i would play like a week... like 1 or 2 hours each day of 1 week or 1 week and a half... so i stopped playing...
So i started playing Guild wars... can play when i want, withouth worrying with payment, and im so stoked with gw2 :3 !!!!