In the broadest terms, it’s easy to know what makes you stop playing an MMO. Specifically, you’re just not having fun any more, or at least not enough fun to make it worth the effort. But there are still changes that cause you to slip over the edge to “this isn’t fun any more,” like realizing that the game is still catering to a player type that you no longer adhere to, or finding out that the stories you liked to read about are over and done with, or knowing that there’s never going to be another real update to the content in the game.
Some of you reading this don’t have a main MMO, of course, and thus you need not answer. But for those of us who do have one… what would cause you to stop playing it? What sort of changes, either on the development level or in the actual game, would make it no longer worth the effort? We’re not talking about shutdowns here, since then you can’t play; what would make you choose not to play?