It all started out with MUDs. There's always been lots of big and plenty of small MUDs, and always a fairly steady number of MUSHes. MUCKs don't count since they are basically all furry dragon roleplay.
Hell there's even like three MLP based roleplaying MUSHes. The one I admin on is reasonably all-ages and takes a dim view of, uh, Tapestries-like activity (read 'strictly forbidden'), while still keeping regular fun inclusive plots going just about every night. And while some of the old MU*s have long since fallen into cliques, there's always new blood and always new places. No...the MUSH community is alive and well, all you have to do is go looking for it. Finding the perfect place has never been an instant easy process except in hindsight.
(An ElfQuest MUSH got me onto the Internet back in like...'94, so.)
It does kinda make me sad that there are more MLP players than Pern players right now, and all the ElfQuest ones are at least a decade dead, but oh well, life goes on and I'll always have my logfiles~.
Oh yeah, and if you remove MUDs from the picture here:
http://mudstats.com/ you'll find that there are about 2700 players on MUSHes/MUXes right now, and 1500 on MUCKs. Furthermore, not even half of those places are 'adult' or 'furry'. There's also like five hundred MOO players, but as far as I can tell they idle all the time (max players per day - min players per day). MUSHes on the other hand, have way more swing, which means that most places are not populated by people who just idle for days at a time!
The best MUSH experience has always been on a game where you can get to personally know and be friends with a large chunk of the population. For me, that means oh...15-60 regulars. With 2700 players on MUSHes/MUXes alone, that's an awful lot of varied, active places to play.
Oh yeah, and while I already keep editing this post, I just wanna say I find it
fascinating how many posters on these forums are familiar with Tapestries.