Oh cool i want the TBC design philosophy back aswell!That's the primary reason I think wow subs have been in decline more or less for 5 expansions straight(since wotlk). Let me explain though. Back in wotlk raiding was still this sort of new and exciting thing for most people who were playing the game. It honestly felt like everyone was into it back then. It seems like a huge % of people still playing wow started during wotlk or earlier. The problem is i think the % of those people who still want to raid on a regular basis is deceasing by about 10-15% each exp since then. Bliz has tried a few things to get people to stick around for other end game content with the only partial success I would say being M+ dungeons. Its just not good enough though. So many players who come back for new expansions now are only doing it to dust off some of their older characters and see the sights for a while then leave again.
The other problem is the degree to which the community cries when Bliz provides any other way besides raiding to get good gear. Why are people so obsessed with raiding being the only good way to get gear in this game? Without progression people won't play. ie The game desperately needs other ways to get gear even if its something as easy as warfronts. Which is why they are bringing in a new currency for 8.1. People need to give up the entitlement. Let Bliz explore new forms of end game content that go right alongside raiding and dungeons. Its time. The amount of time being put into raids by the dev teams needs to be cut in half so they can actually polish these other things well enough that people might find them to be fun and worth doing. Raiding is going to be the anchor that sinks this game if it doesn't find a way to innovate itself.