One opinion I wanted to bring up in this thread was that each game really should have a firm design from the ground up. That doesn't mean it ought to be 'complete' on day 1 - or even day 365 - since that isn't feasible (or even fun). But it does mean each game ought to have its principal administrators put in some honest thought in how it's different than every other MU*; why does it even have to exist? What are their goals? What excites them to create this new thing? What would make it exciting for players to come in and participate?
It always drove me a little crazy when the whole process became "let's put this new thing out with as little work as possible, as soon as possible". I've maintained that thought through the years because this is the whole thing about a MUSH - the possibilities are endless. You're basically staging an interactive, multiplayer novel-slash-improv theatrical production whose characters can be any damn thing you choose, you can set it on any stage (today's Earth, a galaxy far far away, Westeros, Gotham City, anywhere)... so why would you choose to just copy/paste what the last three MU* did pretty much verbatim, slap a new name on it and call it a day?
And this kind of hurried let's-just-go-ahead process can infect other important decision making due to the lack of a central focus or guiding set of principles throughout the way an entire MUSH is being ran. Decisions get made in a hurry without real thought behind them; for example it's very common to see fledgling games create a larger issue than what they're trying to solve by creating hoops good players need to (and will, since that's what makes them good) jump through trying to prevent the symptoms of bad players' behavior - only most often they won't, since those folks will ignore or go around the obstacle to get what they want, since that's what makes them bad. The result is alienating the former and barely inconveniencing the latter. The cause varies.
Another example is games which simply copy house rules or policies from other MU*, a tactic that can result in perpetuated systemic issues, mixed signals and conflicting goals if other aspects of those games don't match them. For instance one sphere can be ran very liberally ("spend your XPs, y'all!") while another in a draconian fashion ("to buy Renown 3 you need to cut yourself and show me the wound") or treat PrPs as an afterthought or even a net negative - and all of that results in isolationism, not being able to create any kind of sustainable culture not to mention - quite often - a revolting door of staff who come in and go right back out.