I've been on APUG for some time now, and I joined specifically because I needed to know more about the technical side of things, especially in the darkroom. I also like to collect cameras, having more than 25 already, covering multiple formats. I don't think of this site (or any other photo site) as being an old boys club until threads like this get started, or when men start to bicker and fight online. As others have mentioned, I've taken part in many photo classes and workshops, and with the exception of one, they've all been mostly women participating (or teaching). What happens online is not a reflection of what happens in the real world.
Also, I think it's important not to let your "impressions" become facts. The gender ratio on APUG is not 95% male. I'm sure Sean could provide the real stats, but this thread has generally shown a 80/20 split over the years. That being said, I know that in the past there seemed to be more women participating in the forums, and it seems less now. And if you'll permit me a generalization -- a lot of women work, take care of the kids, their parents, housework, etc. (more than most men) -- if they do have time to pursue their hobbies, they're actually doing it and not sitting in front of a computer talking about it. I can because I am single and I don't have to worry about anyone other than myself, which gives me time to spend online and in other places.