An added side of this comes where the user expectations change the game, forcing it into (or at least towards) the mold they expected.

I read an article once (I wish I could find it -- it was very good) on how MMOs, as a genre, were essentially unsustainable. To summarize, every MMO has its good points and bad points; when you leave from one MMO to another, you presumably leave because the bad points made the good points no longer worth it. (There was more to it than this, like the "short-term bad but long-term good" idea, but that's the gist for this conversation.)
The problem is your ideas on "What an MMO is" were formed by the MMO you just left because it was bad. You now compare the new MMO to your model MMO and gripe about everything that doesn't fit it; the MMO changes to fit the old ideas, both good and (more frequently) bad, and becomes the new model -- most likely worse than the first.
Then you move to another MMO with your new model, and the process repeats itself...
(If someone could find the actual article, I'd greatly appreciate it. It's articulated much more nicely.)


I sometimes wonder just how much different genres are held back by their "best" examples. Starcraft, HalfLife, etc. may be great games, but how many better games have been scrapped because of their popularity?
More importantly, how does the developer move past them?