I think we agree that the assumption that "removing interviewer/managerial bias will result in a gender ratio of 50%" is false. The variability of sex differences in vocational interests probably accounts for more of the gap than bias in the hiring process, i.e. "mean old white men". I can also accept that physiology influences cognition, although where we disagree is how much of a factor that is in the gender gap, or how relevant it is to any sort of policy decision.
Removing bias in the hiring process wont solve the gender gap entirely, but it will help it.
Telling girls that they can do and be whatever they want wont solve the gender gap entirely, but it will help it.
Changing the masculine and sexist culture in STEM wont completely solve the issue either.
There is basically nothing that can remove the hypothetical physiological factors contributing to gender disparity in STEM fields. So why are we even talking about it? It derails the conversation. There are things that can be done, and we should do them. Until we reach the limit of what is possible according to your hypothetical physiological explanation, why bother even bringing it up?
What a strange comment (you don't paraphrase; you caricature)! I'm not saying any of this! Where did you get the impression that I was?
I agree with all your points, btw. The existence of these differences doesn't enlighten us as to their causes, proximal or distal.
Rather, we have much evidence showing that anatomy and physiology influence cognition. Does this explain the gender gap completely? That's unlikely, but it's equally unlikely that the gender gap would disappear if only the "mean old white men stopped being jerks".
tl;dr: if we're going to have an honest debate, we have to entertain the notion that at least part of the gender gap is the result of "nature".