The correct takeaway from this, however, is not “herp derp, women can’t do math.” It’s that the social costs of sexism are really, really high. If, despite massive cultural and institutional barriers, significant numbers of women were making important contributions at the highest level all along, but denied credit, that would obviously be grossly unfair to the women in question. But it would be sort of a wash from the perspective of overall social utility: The allocation of credit is different, but society still gets the benefit of the brightest women’s contributions. The grimmer alternative is not that the wrong people get the credit, but that important innovations just don’t happen because the pool of brainpower available to tackle important social goals is needlessly halved—the potential female counterparts of Vint Cerf and Bob Kahn never got the opportunity to accelerate the progress of the Internet because, at the time, hostile institutions froze them out, or antiquated norms of femininity deterred them from obtaining STEM educations in the first place. That’s a much, much bigger loss.
There's a direct cost to institutions as well, when women are forced into marginal roles. As a concrete example, sexism is one of the reasons Xerox doesn't own everything.