I’ve only just caught up with this thread. It’s an interesting discussion, but one thing hasn’t been mentioned. Some wargamers are very hostile to the idea of female wargamers, and presumably that’s a barrier, at least to women.
I don’t know where the hostility comes from, but I’ve seen plenty of examples, mostly online, and heard horror stories from women.
The only solution I can see to this particular issue is for those of us that don’t agree with it to speak up when it happens. Even if you don’t change the attitude of the person you disagree with, if their voice isn’t challenged, it’s easy for outsiders to assume that everyone agrees with them.