My immediate thoughts were a) there are plenty of them on LJ, but of course b) LJ doesn't count. Why LJ doesn't count when bloggers discuss blogs, and why there are plenty of women here strike me as interesting questions.
There are a lot of people who don't really consider LJ a blog. Certainly LJ has the reputation for being an insular place where people talk mainly to and about their friends on subjects that are only of interest to themselves.
Personally, I don't actually mind the reputation, because by and large--aside from the food and lodging listings--that's why I blog.
LJ's focus on people you actually know may be more attractive to people who care more about social interaction. My gut feeling is that this tends--for cultural reasons, perhaps--to attract more women.
To be fair, Crooked Timber was originally talking about academic blogs. Oxblog theorizes that women may not be so eager to join the cut and thrust of online argument. It might be, though, that we social people have other things to talk about.