The wage-gap argument doesn't even make sense. Just imagine if a company could get the same productivity out of women and pay them 30% less. It would have an enormous competitive advantage over every other company in its industry and all the companies would quickly be forced to either hire all women themselves or go out of business, not because of any misguided government interference, but purely because of overwhelming free-market forces. The same argument applies for women in the boardroom. If they gave a company a distinct competitive advantage, every company would already be forced by the market to have lots of them.
You are being very stupid. Your basic mistake is in assuming that the free market is 100% efficient and free of prejudice. What on earth gives you that impression? Hiring and firing responds to the trends of the day. Why do you think the participation of women in the economy has been changing over time? Why do you think the wage-gap has been changing? Why is the level of the pay gap perfect and just today, of all days, when it wasn't back in the 90s, the 80s, the 70s or the 1840s?
The fact is, prejudice exists despite the fact that it creates inefficiencies and makes more prejudiced people and companies perform worse. Because prejudice takes time to work itself out of the system! The Nazis refused to allow women into their munitions factories all the way until the end, even though this terrible decision contributed to their defeat to the Soviets who did so, and even put women into the front lines. If your argument was correct, the Nazis would never have done so, they would have seen the effects of their prejudices coming a long way off. But they didn't because they were idiots and in the real world there are a lot of idiots.
Ellen Pao's experiment, whether it works or not, is part of the process whereby inefficiencies are removed from the system. To do so, after all, people need to try different things. People like you, who think the status quo is perfect already, have always existed, and have successively been proven wrong again and again throughout history.