Yeah, it just seems to me that girls are under a lot of peer pressure to pursue social, status-raising activities. Sitting in front of a PC hammering-away Java for 5 hours a day isn't very glamorous, exciting, or social, and there's the "nerd" stigma associated with it.
Even women who are naturally inclined to pursue Comp Sci or engineering do so to pursue careers in finance or business, and make more money, not necessarily because they love computers. And moreover women who are employed by tech-companies usually work in the non-technical areas, like PR, marketing, sales, etc.
If Google wants more women in tech, they should make coding (a solitary and unglamorous pursuit) look cool, exciting, and socially positive. Maybe they need a Java Camel.