I think the cliche that women don't watch porn goes hand in hand with the perception that women don't want sex as much as men. In my experience, neither of those thoughts are true. I think it also has something to do with men looking down on (or being intimated by) women who are sexual creatures.
Redtube can be awesome, but I prefer Tumblr for my porn. All the sexy gifs and videos I want with less popups and seemingly less viruses.