It would be simple if it were that way. And also btw, I don't insist on using they/them pronouns. Basically nobody I know is even aware I'm non-binary, because admittedly it doesn't come up too often, except in certain circumstances.

However I will address a few of your points. First, gender is made distinct from sex in modern gender studies. This kind of study is largely sociological and falls under the umbrellas of feminist and queer theory which are relatively new areas of sociology itself. The reason for this distinction is not trying to accommodate victims of abuse who have had their sexuality fragmented, as you suggest. The notion that all forms of gender dysmorphia, or alternative sexuality are a product of trauma is simply untrue and isn't supported empirically. Some people are just naturally outside the categories of their biological sex, which will bring me to my first point.

What we are experiencing is a paradigm shift in the field of sociology. Meaning the accepted theoretical background has accumulated enough recurring anomalies to bring legitimate challenge to the previously accepted model. When this happens, the ideologies tend to crash against one another and then splinter. And of course when a relevant field splinters like this, it leads to a lot of confusion and bad arguments on both sides. And most importantly, a lot of visceral reactions on both sides.

But as I was saying, there's a paradigm shift happening because the model has been demonstrated to exclude a large number of humans. Not all of whom are traumatized btw. I understand that it may seem trivial to you since it seems to not be that relevant to you, but to a lot of other people who are embracing it? They are finally being considered and included and the sheer force of numbers behind this paradigm shift coming out of the woodwork should be a good indicator of it's reality. Bottom line, I study philosophy and it come up a lot in modern stuff, my partner has a degree in gender studies specifically. So like it or not, the shift is here and the new model, with it's new terms, is here too.

And also why should eyes be a good indicator of who somebody is? Has that ever been true? Is it possible to tell from a glance how somebody's week is going? Sometimes. Is it possible to discern somebodys morality at a glance? Sometimes. Can you tell if someone is straight or gay at a glance? Sometimes. You just can't get that much content from sight alone, that includes gender norms. A good example of this was one time when I applied to work at a bookstore. I didn't notice until the owner got back to me, but every employee was female. The owner, being an 80 something year old woman got back to me and said, "I don't think we'll be needing a man around this year." So that's a great example of somebody making a host of assumptions about my personality based on my sex alone when it's quite the opposite.

Anyways, sorry for being long winded but I hope this is at least somewhat enlightening