I usually find arguments about how "underrepresented group X in upper management will somehow make the company better" unconvincing, but the downfall of Bear Sterns is a great and decisively convincing example of how a monoculture with a lack of multiple perspectives and backgrounds created a really corrupt and toxic environment. At the very least, the sexism towards women in the corporate culture should've been seen as warning indicator for their business practices as well.
In this case, I think sexism was as much a symptom as a cause, and the larger cultural problems were very destructive to women, men, and the US economy.