Female leaders improves ROI?

Fact: the data has shown that female-led companies generate a higher return on investment in invested capital, equity, sales and earnings. Fortune 500 companies who had at least three female directors saw increases of 53 percent return on equity, 42 percent return on sales and 66 percent return on invested capital. Why are there not enough women running companies especially in tech?
In advertising women have made significant strives...In the US the 3% movement has been pushing this agenda with creative directors...more diversity = more creativity = more profitability. And that seems to be creating dialogue. (http://www.3percentconf.com/about). My own personal observation is that there are still less women really running p&l's and that ageism and "expiration dates" continue to be a reality.
In tech, the issues are magnified. "Silicon Valley has struggled for years with diversity and inclusion, as critics have wondered whether the industry can achieve its grand self-image: a bunch of brilliant minds set on making the world a better place, for whom no problem is too tough to solve, no status quo too established to upend. Despite whistle-blowing at other companies about hostile office cultures and widespread acknowledgement that the industry needs to “do better” when it comes to hiring and retaining women and people of color, those problems have persisted.". Here is an interesting article on UBER that brings up many issues.
Only 7% of VC's are women...Is that part of the problem? Debating this over coffee today.