Based on my own experiences, I believe this is a result of a more fundamental difference between men and women. There doesn't seem to be many females on
any forum dedicated to a specific topic, no matter what that topic is. When males want to discuss something, they often form special interest groups for that topic. When females discuss the same topics, they seem to prefer to do so with friends on social networks, or use generic female-only forums.
PS: I live in a country that is surprisingly gender-segregated, so YMMV.
