Came here just to say this and glad to see someone already did. Put another way: the observation of current reality is not a mandate of how things "should be" or that something "is natural". The justification of present gender-based differentiation by looking at biological and psychological factors is post-hoc. People are looking for evidence to fit the conclusion they've already come to. Our culture creates our reality and, if we work consciously to change culture, that means we can change our reality through culture shift.
Sure, it's hard to pursue such big potential changes without knowing whether there truly is a biological basis for the difference in gender participation by career (we don't have baseline "neutral" data, only that from existing cultures), but it should be easy to agree that treating people equally and allowing them to make their own unbiased, uncoerced decisions is the ideal to strive for. Otherwise we're just deciding that we are more comfortable upholding existing cultural norms than actually providing a level playing field.