Yoshi's right in terms of the big picture, think of a MMO like running a casino: you don't give comps to the shark big-time winners, you give comps to the casual big losers. Why: because they are much more in need of something to keep their interest (and give you money) than the sharks (the sharks already will stay because they win).

Consequently, there's not enough marginal benefit from attempting to pander the "raiders" or whatever other designation you give to the hardcore folks. Even if they burn through content real quick (cause they hardcore), they are going to do that no matter what and they'll come back on a fairly regular basis. On the other hand, focusing on the hardcore risks a total collapse: the hardcore people (borrowing someone else's quote) burn through content faster than normal human levels no matter what and there will be high attrition from everyone else (because they're going to get gated hard). Hence you lose the "hardcore bored" people AND everyone else, a classic double negative.