Frankly, I agree with you. I think a real challenge for game developers is creating a game that is friendly to both casual and hardcore players, and everything in between. The problem largely lies with the players themselves, though. Hardcore players have this strange habit of wanting challenge, yet refusing to actually interact with the challenging content. They simultaneously want a faceroll, while complaining that everything is too easy. Games also have a consumer culture. When players' toys get old and out of fashion, they throw them away. Most MMOs in existence are effectively made up of 5-20 pieces of content. Everything else, as fun as it was (and still is, if people cared to do it), is considered worthless.