Do MUDs count as MMORPGs?
Depends on who you ask.
Someone like Bartle would (does) claim they are the same because he studies them and inclusion expands his domain.
By percent, MUDs and MUSHes and MOOs were real big in the beginning. There was no "world wide web" yet, so email and chatting (arguing) on mail lists were what you did. Text-based games offered unique entertainment and a chance to deal with people all over the world. Of course, in the beginning of the internet, you were a scientist or college student so literacy was assured. The newbies from AOL didn't like those games much though, because you had to read stuff. Okay, you had to read
everything. So as the numbers on the internet grew, text-based games only became slightly more popular.
The first "MMOPRG" I was aware of was WOW. And we hated it. Absolutely loathed it. It was the enemy, stealing our players. Making things too easy with pretty pictures. Replacing roleplay with.... We styled ourselves after 20th Century authors bemoaning the onset of the silver screen, wishing everyone would just read and use their imagination. Well, you know how that turns out. Name a well-paid author without a movie deal, please.
So, despite learned assertions to the contrary, in a popular sense MMOs and MMORPGs are separate from text-based games, the latter being seen as the equivalent of a giving a pennyfarthing bicycle to a woman that wants a Hummer to take her kids on vacation. Not at all equal and only vaguely similar.
Physical details of the games aside, though, I think
the players are the same. And while I'm sure there were a lot of "it's a passing phase in college" type players, I bet many of my nemeses from those early days are still out there griefing new players.
Anyway, we closed the MUD in 2012 and two years later I found SL through a Poser forum. I tried an MMO (GW2) for the first time 3 years ago. I still poke around BDO a bit because I like the combat system, but I'm still waiting for the next big one.