You need a warrior's mentality to bite the bullet / grin and bear it / do what needs to be done for the company to be successful, or it will fail. Long hours, insurmountable goals, head-to-head teams, killing the bad ideas early. If women can roll with that, GREAT, they can join the ranks and be one of the guys. But women don't have that testosterone flowing in their veins to operate on that level. Startups are like an extreme sport, yes there are some extreme women but it's MOSTLY men, because our testosterone fuels our desire to outperform, over-excel and become #1. This is why the top elite bankers and day traders are also men.
At some point we need to step away from the "58 genders everyone can identify as an apache helicopter" mentality plaguing our society and accept the physical, emotional, and mental differences in our biochemistry as a divider in our abilities as male or female. There's feminine men, and there's masculine women. Their existence does not mean all men can do what women are good at, and vice versa. WE ARE DIFFERENT.