We did have a social group for survivors - I miss it. But my part of why it doesn't exist and I think others is that I go in and out of healing phases. Sometimes I need to talk and then I go for periods of taking time out. I think it is probably really hard for a moderator, who is going through the same phases, to maintain the effort.
One advantage of a private group= there are frequently people on the forum boards who just don't understand, and blame survivors rather than the therapists. It can be really triggering. There were recent posts here which made me want to avoid the general forums, but I've decided to try again. Yes, we need to use the opportunity to help people understand, but sometimes it is just too hard to deal with their comments.