Why do we reduce people's romantic orientation to their sexual interests? Why not say "romantic orientation" instead?

Earlier today I was in a comment thread with someone who was making the silly argument that children shouldnt be at Pride events because "it's sexual".

I explained that Pride isn't about gay sex, it's about queer people's freedom to be themselves and to love who they love.

They didn't care.

Their silly argument basically boiled down to "homoSEXUALITY is SEXUALITY and it's inappropriate for children to be exposed to SEXUALITY".

Again I attempted to explain that "sexuality" refers to the set of people someone is romantically interested in, not exclusively about who they want to fuck.

But nonetheless the idiot continued their bad argument.

But it made me wonder, why do we say "sexual orientation" rather than "romantic orientation" or something similar?

Why reduce people's romantic interests down to sex?

Why not say "she's homoromantic" rather than "homosexual" and make the terms about who people love rather than who they like to fuck?

What do you think?