There is a masochist bent to many CS programs, where students are basically told that they need to "sink or swim", then get pushed into the water. I saw more than a few people just hit a wall and give up.

I think that in general, women tend to thrive in different circumstances than men. A big part of the way that CS is presented to students is that it is a "lone wolf" endeavor, and students are expected to just figure stuff out. That appeals to the hardcore, anti-social nerds and feeds the male ego. It's not appealing to women or most men.

The IT team that I run now is probably 60% female. They rock, and only one of them has a degree in CS. It's a real shame that in a field where top companies claim to be short on talent, keyword filtering is virtually eliminating half of the potential workforce.