Personal opinion:
Note, I’m neutral to both sides cause I’m not going to be on someone’s side, if it’s right or wrong.
This „standard“ stuck from old ages as we know, and back then people didn’t allow/ punish people to confess, so only two genders were made.
And a fact, (it’s not That I think is bad or something) % of hate in society has grown equally to tolerance these days because the world has made such a diversity in the past years.