Oh yes indeed. There's a whole non-mainstream Jazz world that really never gets any discussion, mostly because no one knows about it, you really have to be an insider to be hip to it...
I used to read the Funny Rat thread, but rarely contributed to it. I had a problem with certain musicians - "non-mainstream", as you put it - being isolated from the rest of the music. I try not to listen to music in that way, and I think it would be a good thing if and when people had something to say about "non-mainstream" musics, musicians, or labels, they would post their comments in normal fashion, rather than posting them in an isolated thread. I think that's happened to some degree since the Funny Rat thread has faded, though some musicians who were mentioned in F.R. seem to be ignored now. The Funny Rat thread may have begun with good intentions, but it became a kind of insiders' club, with a limited group of people talking with each other. At least, that was my take - not a good thing for the music, imo.