It is OK because caring is loving. From those who can, for those who need. If a profession demands masculine traits (consider underground mining) then it should be performed by those who can make the most of it. If we insist on having under performing people on those positions based on some ideology then all will suffer . When someone dies we will have to face the reality that the cure could have been here now if the local mining facility had produced more steel, to make one more car, to get that researcher to the lab in time, to produce the cure. Everything has consequences, and it is logical that we should do our best.

Given that men and women are very different, if people are allowed to or even incentivised to do what they are good at and/or want to do then of course you will end up with industries being more or less dominated by either gender. The only way you won't get that is by not allowing people to do what they're good at because of their genitalia which I think is very much not ok. Or perhaps if men and women weren't very different, which they obviously are.

Yeah, it's unfair to women that men get to do all the plumbing, mining, construction, warfare, etc. demand equality!

And to flip that around again, why is it OK to have the majority of college admissions going to women? Especially in some fields women dominate, e.g. 95% of veterinary students are women. Is that OK and if so, why is the opposite a problem?