I started play wow since 2007 at Darkspear EU and came back to China from 2009, just right after 3.1 released. So I have witnessed the whole TBC to recent, from EU to China. So, the following are what I am thinking and the reason that I thought why people is leaving wow.
1, The Class balance. Here I'm talking about nerfing classes. The "Class Balance" Blizzard have talked a lot but do they really think the "BALANCE POINT" really exist? I think most people do not think that way. Then why chasing that thing so focus if it is not even exist? For me in personal I don't think all class should be balance so much. There are 11 classes and 34 specs but there is only 1 class/spec will be on top. People will not all go and play the top class and left the other class behind unless the rest class are pure incompatible. If all class felt strong then people might just choose what class they want to play, not to pick up the one who will be bought to raid or the one that get less chance to get nerfed in the future.
2, Nerfs. We all knew that blizzard loves to nerf class and people have nothing to do with it but leave. Especially the nerf that caused because of PVP. PVE have a much player base than PVP but PVE player have been keep paying for one thing that they dont really care. I knew PVPer may not happy to see what I said but I'm telling the truth. There were some unique class ability was really nice but they are all gone and soon will be gone. For instance, Shadow form use to be the most powerful talent which gives you off/def increase. Now the damage decrease will be nerfed on 5.4 and the heal amount is getting nerfed before 5.4 if I remembered right. Why doing this? Because shadow priest is too powerful in arena. What about the shadow priest never go to arena like myself? I knew for some abilities that deal less damage on players, then why not make all spells you are going to nerf because of arena balance in that way? For spells get nerfed because of a boss fight, here is my word: Buff the boss then!
3, Dailies. I knew that at the end of cata there are some player complain that they have nothing to do when they log on, so they made tons of dailies to do at the beginning of the mist. I think there is a mistake. People don't want to logon and nothing to do and they don't like to get forced to do things. Beginning of mist is to force people to do things. People have to do dailies for the rep to buy items. I do agree that people should do some work for the reward but not at 11:30 pm after raid then spent another hour and half for dailies to help progressing. Imagine that you have been worked from 9-5 and after you get home and set everything up then logon until 11:00 pm the raid disband, and then you have to spend another hour and half for rep grinding. It is way too much to do so for me I chose to afk until 4 weeks ago my mate asked me to come back to play a bit just to see what 5.4 is. It is not feeling good if you are forced to do things.
4, DK. At beginning of Wotlk that Death Knight is a hero class but now we don't really see how does it look like a heroic class. For Blood, it is ok for tanking but with the worst mobility compared to another 4 tank class. For Frost, dual-wield is dead and the mastery is scaling so bad and we don't see that blizzard will change it at all. 2-handed frost is still at a pointless position to play. And for unholy, it doesn't feel that you are playing a melee class at all. The top damage spell are disease. and when you wave your weapon you just feel that you are hitting in air for nothing. Then back to the beginning, WHAT MAKES DK A HERO CLASS?
P.S Maybe some one could move this to US or EU official forum as well, please? I cancelled my subscription since 2009 so I cannot post anything there.
Another P.S I am still playing but not on EU/US realm. My realm is called Dark Iron in China. So I DO know what is going on recently I do know they just buffed DK couple of days ago.