Existence is its own justification.

Yes. This. Having settings that don't just default to what the author assumes is 'normal' is good for everyone, but especially kids who need to know that people like them can have lives outside of Very Special Episodes about bigotry. (Those Very Special Episodes might have been important steps, but they aren't the destination.)

Reminds me how I loved stories of girls dressing up as boys and proving they were "just as good" as the boys (hey, boys were the only ones who got to do anything interesting in these stories otherwise...) when I was a kid, but nowadays I'm more like, "yeah, we know. We've known for decades, you just weren't listening", and rolling my eyes.

Yes. While this is still a story one can tell*, it shouldn't be the only story.

* Because some people apparently still need to hear it, and it was a thing that happened in history.

But I never wanted to be a boy and go fight (or fight as a girl) and I wonder where are the stories of boys who want to stay home and help with the family? OK, not much traditional 'go -out- and save the world' can happen staying home, but why does 'just as good' STILL mean that boys are better, we want to be like the boys?

Because sexism. Shades of the millennia of considering men people, and women property. It's not dead yet.

Anyway, switching from stories to real world - my real world, that is - I am interested in computers. I studied computer science. Among other things this involved a maths prof telling our class that women tend to have more trouble with the subject than men, and five minutes later telling a female student her answer to a question was wrong, when in fact it was correct. Also, quite frequenty being treated as if I had two heads when I tell people I'm a programmer, because it's OMG SO UNUSUAL for a woman not to be ignorant about tech.

I like programming not BECAUSE it is "male" (my mother is WAY more computer-literate than my father, so that idea didn't even occur to me before ending up nearly the only girl in a computer science class), but because that kind of problem solving appeals to me.
I don't like babies, not BECAUSE liking babies is "female", but because they fall somewhere in the uncanny valley for me, and besides I'm terrified about messing up the life of someone who is dependent on me.

I like seeing women in "masculine" roles because it gives me a right to exist, and I ALSO like seeing men in "feminine" roles because it shows that being "feminine" is not too icky for men to be.

I can understand frustration about lack of positive and interesting representations of more traditionally feminine women, as opposed to women who are action heroes. I'd like to see more stories that feature women as protagonists, and shaping the story, no matter how. (I remember a wonderful scene that involved a princess who had just gotten out of an unwanted bethrotal taking steps against a repeat: By looking for a husband on the basis of "is he not old enough to be my father, and does the resulting alliance give my country access to a seaport?". She sent out a guy to do the actual negotiating, but it was her decision.)

But I've seen discussions of that turn into female characters who kick ass "men with boobs", and saying that all female characters should be gentle and nurturing because that's how women ARE, and the latter is denying women like me the right to exist. This bothers me a lot.

Sexism is a load of bullshit. It's pretending that there exist only two boxes of traits and interests, and any person can fit only one of them. It's monumentally stupid. Punishing people for showing interest in something from "the wrong box" is in my view bullying and evil, but it is, sadly, completely normal.

Woo hoo! I caught that reference! Curse of Chalion, by Lois McMaster Bujold.

Princess, I know just what you want for a betrothal gift!
A seaport?
Uh, no, a string of pearls as long as you are tall!
Yawn.

Fabulous book. Fabulous author.