There are myriads of women that like watching football, but there are FAR fewer that like to talk about it, especially in the minutia that you'll find on a website.
Listen to the sports call in shows, again, there are far fewer women calling in. Nothing sinister in it IMHO; just a difference in preferences.
My wife would never post here but is at least as big a football fan as I am. (She catches as many college games as possible.)