The thing is, the people promoting this blurring of lines crap are kind of right-- Humans are not that dimorphic a species, especially psychologically. But it's the same exact way that Marx's criticism of capitalism was kind of right. I.E. based more in resentment to the status quo (which keeps us all alive) than to helping the afflicted, and disastrous if implemented in reality.
Roles are important-- they keep society together, keep itt functioning, and (probably as a result) living out a role is the surest way to attain personal fulfillment.
Yes, men have brain structures that first evolved in women and vice versa. It's why fathers take care of their kids beyond sperm donation, and why women are more than simple broodmares.
Just because you live like a man and perform your manly duties and all the rest doesn't mean that's all you are. That's just the face you present to the world for practical reasons. Yes, I may have a sensitive side, I may love flowers, poetry, the laughter of children but if we're serving together in the goddamn trenches all you care about is whether I can be relied upon to lay down covering fire during an advance (and yes I think I could).
These people think they're oppressed because other people feel disgust for them. Maybe they're right-- but disgust isn't just a means to ostracize people who don't fit in. Most people feel more internal disgust for their own tendencies that need to be repressed so they can serve their role properly. It's an extremely delicate system we really don't want to mess with, at least not with revolutionary fervor.
When you get older and mature, more secure in your position in the world, you can start exploring other aspects of your personality. But if you're young and confused that shit is just overwhelming and can lead to ruin. This is especially true for creative and open people, who are the types society really needs to reach adulthood stable and productive.