I'd say it's a symptom of social handicapation, rather than the inverse. As a matter of fact I think being on the forum in itself is a minor symptom of social frustration
You go hunting for online interaction because there are no social cues involved, so it's easy to feel included. When you still fail to be included because you're a turbocreep, you move on to communities made up of people whose entire personalities revolve around some sort of incredibly undesirable trait, forcing them to include everyone due to the fact that they are the lowest possible common denominator in social hierarchy. In the case of furries, the undesirable trait is a degenerate special interest.