"And I don't see how being disrespectful of that is any better than being disrespectful of someone's true gender or sexual orientation."
Given that demanding to know a non-binary person's downstairs mixup is patently rude and can be triggering for people with body disphoria, yeah it is pretty different.
For me it's a constant reminder that I will never escape the body I was stuck with and that it will always define me in some way despite my wishes. So like, yeah, seeing shit like that fucking sucks.