Someone telling you that you aren't who you are is a really bad thing. It is not dying at the hands of a murderous cop, but it's literally insulting your very being.
you misgender people for a whole list of reasons,especially so when you present yourself the opposite of what you identified with.
it's an insult to associate misgendering someone as assult when a whole group of people who were once persecuted/assulted/ostracized based on their race,skin color, belief and sexual orientation.