I've had talks in the past trying to guess what possesses people to go to a certain kind of game looking for content that doesn't quite match what its theme is about.
The obvious case (which I don't want the thread to be consumed by) is sex. Some players don't go to Shang but instead to newVampireMUSH, and I'm not talking about stalkers or jerks here but just regular players who want a very large portion of their RP to be about TS, yet they don't choose to play on TS-based MU*.
Or... people who claim they despise certain genres or types of games yet they play them anyway. That doesn't make any sense! If you hate L&L why play on Arx? And if you do what's the point of trying to invent a steam engine or gunpowder or whatever otherwise proclaim the game to be a railroading failure because it doesn't match that very one-sided vision?
The only expectations players should have is for things to be fairly documented and implemented - in other words that procedures are written down ahead of time and staff not screwing them over. Now granted, this has been... known to not be the case.
Otherwise though in many cases expectations weren't fair to begin with. Even when I was participate in a PrP I didn't enjoy too much - perhaps I wasn't given agency, maybe it's too slow, could be that it's too combat based with little story to sink my teeth into, whatever - it's always up to me to leave. I didn't get promised anything, the ST (be it staff or player) doesn't owe me anything.
I feel sometimes we take things for granted in our community, including the time and energy put forth by others for our entertainment. The world outside of MUSHdom isn't our oyster to harvest for our fun as we see fit, so why should a MU* be?