I agree with most of your thoughts, especially that it’s a top of funnel problem. And the solution lies even earlier. Maybe when we start separating pink from blue. It’s not just parenting, it’s school, society, media and everything around us that seems to be giving out this message.
But it’s still important to work on diversity in both directions. Because the two sides aren’t in a vacuum. Young girls probably look up to women in fields other than tech and want to head in that direction. It’s therefore still very important to adopt/retain an affirmative action like approach for diversity (gender and race) in tech.