The tuning of the raids was a failure. It destroyed the social and lower tier guilds. This is a mmo and people do play it for the social ties, those people got slapped down and told to do lfr. That's not what many of them were wanting. Their guilds broke up and those people quit.
The main problem with this expansion is that they bought into everything the hardcore told them and did all they could to please them. As nice as the raids have been in this expansion they have been failures due to tuning. Dragon Soul was small and out for far too long yet managed to keep people playing because it allowed people in it's doors. Now most people are locked out and outside of raids there has been a lack of content.