And if person A refuses to accept person B for who they are, that doesn’t define person B. It defines person A as an asshole.

Agree. And that sentence is not only valid for gender, it’s for any other cultural label (like genders are).

If I say that I’m a gamer, or a fan of star wars, or whatever, and you’re spending your energy trying to convince the world I’m not what I said… it says much more about you than about me.