It's a problem of economic inflation. The games start out easy at release, but developers see the need to tighten their belts to prevent game currency/abilities/skill from being worthless. So the template has been in MMO land for developers to let a few early adopters climb the ladder to the top until they patch the ladder away. Or the opposite, like WoW, just keep it easy and let everyone into the top.

Runescape has a good place to see this with holiday items: http://runescape.wikia.com/wiki/Holiday_rewards

The right way to solve this problem is to keep the game as easy as it was at release, but to implement economic atrophy and redistribution of outcomes. I'm not aware of any game that does this other than Eve Online. I do not play these games but I like thinking about their economics.