I think there's two parts to this, and your 100% correct so don't take this any way but that.
But there's always going to be the outliers where someone's used an incorrect name/pronoun and the other party has taken it far too personally. There was a push to try and classify misgendering as a hate crime for example and instances like that will get people feeling like they're being punished for no real reason.
The other part, quite often the part that riles people is that it it's often not even those who have changed their identity who get angry, often random strangers want to look the most accepting and this get angry for what really doesn't affect them.
Imagine if someone got your name wrong accidentally and whilst you tried to politely remind them some randomer you don't even know calls the other person a right wing gammon, suddenly the conversation isn't about your name or the reasons behind it, it's two people shouting at each other who it doesn't really concern to begin with!
On a slight tangent, again coming from pure ignorance rather than malice- when did we get to the point where people are changing genders based on what appears to be their hobbies and interests?
Gender dysphoria is obviously a thing, but I'm sure it's not as prevelant as social media makes it look, and i was brought up in the 'girls can like action man and boys can like barbie' school days and it seems to have gotten to be 'a boy who likes barbie is really a girl and they should be treated as such'. The pivot baffles me... And i think thats where a lot of push back comes from.