That's a pretty mainstream view divorced from the issue at hand.
It isn't. Tessa describes her identity by comparing herself to "other girls" (as has every non-binary female person I have ever read describing themselves). Implicit in this is the notion that there's a theoretical ideal of girlhood and that those who differ are doing it wrong.
Old fashioned people would tell girls what is or isn't appropriate for girls, newfangled people would tell girls that if they're different from some stereotypical girl then they might not really be girls, and to me this doesn't seem like progress. To me it seems like we've stopped beating gender non-conforming girls with one stick, and started beating them with a different stick.
What does this mean? Feel free to play with gender but for god's sake don't get too invested into it or let it become more central than your precious biological components? Are butch lesbians not an identity? Is "woman" not an expression of identity?
Well that's an excellent question. What actually is an identity, then? People tend to think of things like your nationality or your religion or your sexual orientation or your sex. "I'm a Canadian Muslim man!" for example. Things that have some degree of significance, and some degree of permanence and some degree of observability.
Is "butch lesbian" an identity, or is butch just a description? Am I butch because I like men's shirts and accessories? Am I femme because I have long and luxurious hair? Am I butch on days that I don't wear makeup and femme on days that I do? Aren't butch and femme both kind of subjective, dated, and pointless descriptions anyway? I don't know. Lesbian is an identity, I think. Or it used to be. It used to mean something, but maybe it's just slowly becoming just a genre of
****. I don't know.
Remember those Gamergate goons from a few years back? To those guys, Gamer (with a capital G) was their identity. Is it really an identity, or just a hobby, or maybe a lifestyle? Are lifestyles identities? If someone says "I'm retired" or "I'm an office worker" or "I'm a homemaker" are those identities? What about "I'm a parent!" as an identity? I am guessing that being a parent is probably a more significant factor in your life than almost anything anybody would describe as their identity. Probably more than what brand of church you go to or what country your grandparents came from.
What about the Goth kids? Remember them? Was Goth an identity, or just a phase?
There are all kinds of other alleged identities out there, most of which aren't taken seriously. People who say they identify based on their kinship with various kinds of critters. Or some sexual fetish. The tired joke about "I identify as an attack helicopter" was really not that far off from some of the things people have claimed to identify as. I don't know if anybody has claimed their favorite sports team as an identity, but I wouldn't be surprised. "I'm RaidersGendered so I should be allowed to wear my helmet and war-paint to work." Last month I read somebody on Twitter declaring a new gender identity called AmongUsGendered, based on their enthusiasm for the computer game Among Us. They even designed some Pride flags.
Of course nobody takes that stuff seriously, except (maybe) the people who claim to identify as these things. (I have an icky feeling that many of the people who identify as "otherkin" are completely serious.) Sooooo... what's different about nonbinary? What's the element that makes people treat nonbinary as a legitimate thing, the element that "otherkin" or "AmongUsGender" are lacking? I'd like to pinpoint what the difference is.
I'll respond to more of your post later tonight.
-k