Earlier quoted context omitted.
Do you have an example of where this belief is expressed? Because the common trope afaik is "From each according to his ability , to each according to his needs". What would be the difference in public policy anyways if after-the-fact results differ?
Well, some public policy differences would be continuing to invest ever increasing amounts of money on the worst performers in schools in an attempt to get them up nearer the average. Another might be seeing the lack of women plumbers (or whatever) and deciding that this is both bad and fixable and investing a bunch of money into advertising how awesome plumbing is to girls in school.
I'm not sure I follow. Are you suggesting that we, as a society, should not invest in worst performers? How would we even know beforehand? And how would withdrawing such funding from "bad" schools not affect the opportunity of all of the children of that school?
What's your point about the gender ratios of certain occupations? That it's a waste of money to try to alter?