I don't think the vast majority of people do still have this mindset of the male pilot and the female "hostie". Most people I speak to outside the industry are well aware that a female could be up front just as much as a male pilot.
Of the eight journeys I've made as a passenger in the past nine months I can tell you that once we had a female Captain and once we had a female F/O.
I think you'll find that many peoples views on this in and outside the wannabe community are changing fast if they haven't already.
The ratio of male to female wannabes is probably around 10:1. But this is ratio will be closing down all the time.
As for whether the guys have more ambition than the girls for getting in the pointy bit - I think it purely comes down to whether they actually want to do the job. In other words - does it interest them? It is most likely a case of the job holding no personal attraction for them.
BM.