I meant to reply to this much earlier! Sorry!
I actually had a very similar experience with Furcadia when it came out - as I recall, it came up in an IRC channel I frequented, and so I gave it a shot with a few online friends. I remember being impressed at seeing a graphical world you could inhabit with other people and build your own part of, and vaguely confused that someone somewhere could possibly be running a server that hosted everybody, for free.
I went back once or twice on my own but kind of bounced off it pretty quickly - none of my friends continued using it, and I was more interested in it as a space for doing things with people I already knew than meeting it on its own terms and meeting people there. It just seemed so big and daunting!
Very interesting to read more about it, for sure. Thanks for posting it!