The ones that do, usually do. Mixed boards have better performance. Company's producing products that don't actively drive away some of the market make more sales. Unfortunately people don't always act based on economic best choice, but based on learned behavior.
If it is, great, it'll sort itself out. I was kind of hoping Etsy would resolve this one way or another (they seemed to be heavily feminist as a core corporate value), but I haven't heard much from them lately - which suggests maybe they aren't doing so well?
It may not sort itself out. There could be non-performance reasons why companies behave poorly. Managers could have incentives for bad behavior (they like going to strip clubs with customers, for example) that present principal-agent problems.
I once observed a Japanese subsidiary of an American firm. They gave women the same career opportunities as men. As a result, they could get highly competent women from top schools (who wouldn't want to be office ladies at traditional Japanese firms) even though they couldn't get as competent men. As a result, the women at the subsidiary substantially outperformed the men at every level.