Why would it be silly in the United States? Charging women and men different amounts for an otherwise identical service is prima facie discriminatory.
I don't feel that strongly about this, I'm just saying that every form of equality in every way is impossible. It would be awful to force a woman to pay more for the same labor/time-consuming haircut than a man would pay. I don't know everything about this case, so I may have misunderstood and assumed that Denmark was attempting to artificially make the average female haircut cost the same as a man's. That would be ridiculous, and if women on average request more complicated haircuts than men, people should just live with that. There are plenty of things for which men may, a on average, be more fussy than women. For those things, it would be stupid for men to complain about having to pay more than the average woman. That's what I thought this issue was about, but maybe I was wrong. If the service is identical, then yes, women shouldn't have to pay more than men.