"That's not a matter of disrespecting that person; it's a matter of disrespecting pronoun pins on principle."
Pardon me, but what? You expect the persons wearing the pin to not feel disrespected? Or that the pin will be emotionally damaged by the disrespect?
Well, yes, obviously? They have a pronoun pin. That's not a matter of disrespecting that person (as you note, we do it to everyone); it's a matter of disrespecting pronoun pins on principle.