The problem for me is dailies, heroic mode dungeons and LFR. They are in my opinion some of the most brain dead content I have ever played in any game ever. Pacman on the Atari system was indefinitely more enjoyable in terms of challenge then dailies, heroic mode dungeons or LFR. And while the argument in favor of the faceroll difficulty of the entry level PvE content is that they are optional to not play any of them for a typical normal mode raider is optional in the same way that looting raid bosses is optional. You don't have to loot raid bosses your team kills but you are not doing yourself or any team dumb enough to run with you any favors by failing take the gear that is available.
When MoP came out I tried stay on top of dailies, dungeons and LFR and it burned me out completely. I tried to only log into raid and maybe run a heroic dungeon or LFR once in a while but I felt I was a liability to my team and had became the sort of raider who I normally wouldn't even recruit.
So I've stopped raiding, my groups raiders have mostly found spots in our guild's other teams and I am taking a break from WoW and enjoying other games. My free time is valuable to me and while I have more then enough time to sink twenty some hours a week into gaming I do not have enough time to spend doing content that offers no challenge or enjoyment. While I have no immediate plans to unsub I think it is fairly obvious that in the long term my subscription is in the "at risk" category. If I do leave I will have many good memories of the years spent playing this game however the current model is no longer holding my interest.
I have more to say but I'll stop (for now) before this turns into a wall of text too long for anyone to bother reading xD