So you'd be happy with men in dresses? society governs how we dress, and it wouldn't be appropriate for men and women to dress the same.
In various bits of he South Pacific, men wear skirts (big, massive, burly guys. jonah lomu size guys.)
The whole POINT of examining gender is to strip away the daft stuff that constrains us, and leave the more sensible bits. So men can't bear children. Women are in general less physically strong. But there's no reason a women can't drive a truck, be a surgeon or be an engineer because none of those things are dictated by her immutable biology. Similarly men might quite like to wear a dress, why shouldn't they?
It's about stopping, at the very start, the insidious process that goes:
Girls wear pink frilly things
Boys wear jeans and trainers
Girls sit nicely so they don't get dirty
Boys run around md climb trees
Don't play with that microscope it's not for girls
Engineering is for boys - they like engines and dirt! Girls like playing with dolls.
And ends up with women socialised to be nice. To people please. To be decorative, to be silent, to be passive, to be objects whose worth is dictated by their appearance. While the boys do civil engineering, build bridges and earn the money.
Not putting baby girls in pink sounds so trivial, but it's one of the ways the above happens. Trying to be a bit less gendered about it is one way of helping. It's about removing those social constructs where they don't serve us.
If you need a penis to do it, it's a man thing, if you need female parts to do it it's a woman thing. alnost everything else is up for everyone.