Oooh, wotchers there our Batty dear!
Whorl, I've been playing the mud for some time, though by the standards of many I'm still a clueless newbie (or wet hen). This in itself speaks for the eternal fascination of the place - some of my friends have been around for eight years or more.
And during that, time, o'course, I've acquired plenty of wonderful friends (some of whom I now know irl) and even the occasional sibling - our Bathoffina who posted a review before this one is me sister, fer example.
Now, of course, I'm hopelessly biased, but there are innumerable reasons for this - or rather, as many as there are rooms in the game. Most of these have already been enumerated by the other reviewers, but I will add:
- Nationalities, languages and accents. Learning a language, then practising it over time on the inhabitants of the region until you speak it perfectly (though with a forn accent, natcherly).
- The witches guild! Not that I'm biased, mind ...
- The beginnings of an economy. Goods and services provided by players of different skills to keep up a healthy circulation of cash (the thieves' guild does its best, too).
- Wonderful, fluffy creators.
- The whole of Bes Pelargic. Those creators are geniuses *fluffs our Etain*.
- The fact that, even today, I'm always discovering more about it.
- Evil cabbages of doom!
As to previously mentioned tensions between the cre/player cases .. well, there is rather a division in perception there. But you can't just blame the creators there. Most of them are genuinely fluffy people who do their best for the place because they love it, but y'know? Players DO complain a lot. :) And that gets wearing, and widens the gap.
Analogous to the occasional relationship between the witches guild and everyone else. Try this several times a day and do your best to remain civil:
wossname tells you: giv me free tea now i am a newbie kthxbye!!!11!!!
You tell wossname: Sorry, dearie, this is a new character and can't brew yet.
wossname tells you: where r u????
You tell wossname: Whorl, my old character's locked out atm, and given I can't fly ...
wossname tells you: y do u all hate me???
You tell wossname: Not a clue, dear.
wossname tells you: [expletive expletive adjective expletive]!!1!
You nod amiably at wossname.
>tell wossname: You might find politeness gets you further here, dearie. People respond wonderfully to that.
>wossname is ignoring you and will not have seen your tell. 
Aaaah, the rich, wonderful world of customer service!
But to counterbalance this:
(inertia) Nayeli: i love you guys.
*snuggles our Nayeli*
 Choose your own relatives, folks! It's wonderful!
 Aaaah, footnoting - another grand feature of the mud!
 yes, including sur. :)
 And MOST actually do some work from time to time. *eyes Chug*
 That is actually a pretty accurate rendition of a conversation I had a few days back ... as a rule I do my best to help, but ...