I really don't understand the distinction you're trying to make. I think you're trying to make community too specific. And support meetings are very much clubs by your definition.

Also I haven't had to deal with "awful rainbow clubs". In fact my experience has been the exact opposite. Twelve years ago, I went to a furry convention and ended up joining one of the most accepting communities I've ever seen. And let me tell you, once a community gets to a certain size, it will have Problems™. :)