If anyone tells you that WoW’s subscription losses is because of “X” feature that they personally dislike then slap them with a rabid poodle. There is no one main reason why people unsubscribe and it is self-centered to think that everyone plays the same way you do.
There are many many reasons for sublosses, from general burnout, inability to accept change in ones environment, parents not allowing you to play anymore, getting wife/life/kids/job, growing up and growing out of video games, ect.
I would also note that the video game world of today is vastly different than it was when WoW was steaming along. When it first came out it was one of maybe 4 or 5 MMO’s and very few console games were playable on the internet. WoW came along at the right time and place to take up the majority of internet game savy players and since then the options have expanded far more than the internet game savy playerbase has.
Now there are around 2 dozen MMO’s and probably 4 dozen little mmo’s (look at any walmart pay to play MMO payment card Kiosk like second life) and 3 major consoles that have hundreds upon hundreds of games that can be played on the internet. The applestore has lots of games to download on your iphone or ipad. Hell some people are entertained by silly Facebook games for hours on end. The gamer market is only so big and each gamer only has a finite amount of time in which they can invest in online games.
Is it a surprise that a decade old game has trouble holding on to subs? No, what is surprising is that a decade old game has almost 7x’s the amount of subscribers that a majority of new games have and those games are F2P. All other MMO’s wish they had the problem of loosing 5 million players and only having 7 million players left. They would sell their mothers and grandmothers to have that problem.