I think you're largely correct, but you're probably underestimating how much societal pressure goes into making things this way. Parents taking away the rocket ship is just the tip of the iceberg. Not only are young girls pushed away from science and other subjects that are considered masculine, but they're also socialized to have a "broad range" of interests and not to obsess over any one thing, which is the exact trait that enabled me and many other programmers I know to get ahead in programming. I underestimated it too until I read Unlocking the Clubhouse (http://mitpress.mit.edu/catalog/item/default.asp?tid=8515...) a few months ago.
For problems this large and systemic, significant corrective action and positive reinforcement are required.
I was friends with one highschooler who constantly showed off his math knowledge. He much preferred to leave people (many of whom were poor) with the impression that he was superhuman, rather than proactively explaining that his father was a mathematician, his mother taught him at his Montessori grade school, and his family was very well-off...
I think a significant problem is the self-aggrandizing way males are socialized. Often to intimidate. This interacts badly with how females are pressured to defer and feel inferior.
For problems this large and systemic, significant corrective action and positive reinforcement are required.