Is World of Warcraft more about seeing new content or getting new gear? I realize that they probably both need to exist to have a successful game, but one has to be a greater motivator than the other. I am not buying the argument that they are both equal.
My personally belief is that while many players play the game for different reasons, the largest motivator/reward is seeing content. And this is so because it rings true in our history as being gamers. Look at all the old console games before MMO's existed most of them did not have a gear reward system. You simply played the game trying to beat it because you wanted to see the end. Look at the super mario franchise for example hugely popular and the game had no other rewards besides seeing the end. You become addicted to trying to beat the game.
This is the engine that drives most games. If you don't believe me, then try to imagine a game without a story line and only offers gear advancement. It is possible to have a game without gear advancement and still be successful. But it doesn't work the other way around. And what happens when you finally beat a game? You either stop playing it/forget about it or go trade it in for another game.
Now this is the fundamental reason why end game should be hard. Because once you see the end game content no matter if it's on easy, normal or hardcore you are done.
And the above reasons is why LFR is bad for the game.
I like this hypothesis because it fits in perfectly with the gaming reward system we grew up with. Which in my eye's give it a fair amount of validity.