This mod has always been on the right side of hardcore gaming. The openness of its roleplaying concept is unlike anything I've seen in any other game I've played to this day. I really haven't found any other game/mod like it, so I'll go out on a limb and say that it's one of a kind.
I've joined this community when it was at its highest point, when you'd spend as much as 5 minutes trying to get in on the server due to it being full. Most of the people who played it were playing it because it offered so much more than anything else out on the market for the low-end computer requirements it had. The gap it filled in the market at the time was exactly what players needed. It was a paradise for space nerds with shitty computers, myself included. The PC I had in 2009 couldn't even run Fallout 3, but hell, Disco was so much more fun to me.
But a hardcore mod community cannot survive more than a few years. It needs a constant drive to keep people playing. The moment it stops, it starts to die. People will only entertain themselves for so much before they get tired and leave, which is why .86's release didn't really do much to the activity. People tried out everything new in a few weeks, and things went stagnant again. Too late, people moved on. Its core player base moved on to other things, or grew up. Like Bloodlike, Discovery's name brings in mind dear memories to me, of times when I felt, well... awesome, while shaping the virtual world around me into what became, for a while, home. Eh... I've always had a soft side for these things.

tl;dr: All great things come to an end.