It concerns me when people confuse the idea of gender equality and rights (which I think most reasonable people agree is a good thing) with the idea that men and women's lives have to be the same in all aspects.
I think it is much more harmful to impose a dogmatic belief that forces everyone to lead identical, mono-cultured lives and denies individual choice.
What if I want to go to a single-sex school? Who are you to deny me that choice?