I think this is very important for putting questions like "Why aren't there more women interested in X?" into context. Even restricting it to people who regularly participate in online communities as opposed to using the Internet solely for Wikipedia and Google and funny YouTube videos and Facebook (maybe 15% of the population?), how many people total would be interested in LW? Maybe 0.1% of the men, and maybe 0.05% of the women?

There's no reason to expect those people to be typical along any given dimension, even gender dynamics.