I'm about to say a few reasons why i believe WoW is "dying". I really hope a Blizzard employee is reading this, and I ask you all to debate why the subs are constantly going down.
1- The social aspect of the game is gone: There is a serious lack of player interaction in the game. You don't have to form any bonds within the game in order to succed. Easy LFRs and "Heroics" play a big part in here, since you don't have to communicate anymore in order to come up with a good strategy. Guild perks and rewards also contribue to this situation, right now guilds are a bunch of players groupd in order to increase the guild level and to give players rewards. Guild levels / perks / rewards were a terrible addition to the game, because right now a lot of guilds have no real goals, no real player interaction... they are just a bunch of players looking for guild rewards.
2- The lack of the seems of adventure: Yeah, I know, Pandaria can be a fascinating continent... but the PvE experience there, for casuals, is just ridiculous. Players can basically afk in LFR or just pretend to play during a "heroic" dungeon in order to get gear. There is no fun in doing herocis anymore. I remember back in TBC that heroics required tons of coordination, and CC actually meant something, and you know what? I was FUN!!! I mean, of course there were some very hard heroics, such as Shattred Halls and Shadow labs, but there were "easy" heroics that required a good group effort, such as Hellfire Ramparts. Wipes are part of this game. A ridiculously easy game is a boring game, but a challenging game can last forever!
3- Empty servers: Players want a solution to empty servers, and want a solution NOW! We are tired of "we were talking about solutions" excuses. Servers are falling apart and guilds are closng their doors, it's time to give us a solution instead of promises. (No, CRZ is not a solution, it is actually a problem).
4- Dailies: Valor points + countless dailies and reputations... yeah
5- Alts: MoP is a very alt unfriendly expansion, do I need to say more?
6- The lore: The lore is not that interesting. Look at TBC, we face major characters of WoW's lore, such as illidan, kil'jaeden, kael (twice), Vashj, etc. In WotLK we face the Lich King himself alongside his army (anub arak, kel'thuzad, etc)... But not... we fight some creatures we have never heard of (Mogu, Sha, mantid), waiting to finally kill the warchief that basially noone likes. Another problem is how the alliance lore was poorly developed. I play on the horde side, but I feel pity for all the alliance players who have to put up with that storyline... I mean, where are the Draenei? What about the worgen? and the night elves, what is tyrande doing? And WHY do we have to fight the trolls in the middle of a snowstorm?
7- The gear: Too many tiers of gear, it makes the gamme too complicated and create means to segregate players.
That's all folks! Feel free to talk!