I believe that a person's gender and sexuality can be influenced by external factors and are not fully determined at birth. The fact that "conversion therapy" exists and doesn't work makes this a controversial take. But conversion therapy is literally just abuse, it's like saying, "A bunch of idiots tried hitting gay people with sticks to make them be straight and it didn't work, this is proof that sexuality is purely innate." That's not proof, that's just a way to get the idiots to stop hitting us with sticks, and while there are idiots with sticks around, it's very reasonable to be touchy about this.
But gender is a social construct, so how is it possible that a newborn infant who has had no exposure to society already has a particular social construct that they identify and one or more social constructs that they will inevitably be attracted to once they grow up? Also, we can clearly observe standards of beauty changing over time and across different cultures. Of course the standards of the culture that you're raised in will influence what traits you find attractive, and it feels arbitrary to draw a line at gender. But these are general trends and the ways in which an individual relates to the dominant culture they're raised in are complex and varied. Maybe someday, once all the idiots with sticks have been gulag'd, people (ideally queer people) can study this sort of thing from a descriptivist, sociological perspective, with the rights and validity of queer people viewed completely as a given.
Until then, the discourse is dragged down to chud level and the priority is saying whatever it takes to get them to put down the fucking stick.