Yes it makes perfect sense because those forums are both places dedicated to the discussion of a single thing. Aspergers and other autism spectrum disorders are characterized by "restricted and repetitive interests". A self-selection bias exists because one is much more likely to find and join a forum dedicated to political maps or alternative history fiction if they are obsessed with those topic(s) as one of those "restricted and repetitive interests".
The real question is how come this forum has so many gays, I have no explanation for that
People who are on the internet a lot tend to explore their sexuality a bit, for starters. Also people are more willing to admit their sexual orientation anonymously on an internet forum than in real life.
