why does homophobia exist?

like, I get that maybe there's like, some sort of a religious thing or something but for real, like... what are the fears driving heteronormativity?

my best guess = it's actually a spillover from the general sexual shame assoc w any sexual expression falling outside of the reproductive umbrella - old ppl having sex, children having sex, incest, premarital sex, etc. are all also taboo bc they're not "properly procreative"

but I'm reading a defamation case for class about Kari Simpson who was mad that Rafe Mair compared her to Hitler for opposing pro-LGBTQ messages in public school contexts-

-& she says stuff like "[T]he first casualty of war is truth, the second casualty is our children. How many here will put their hands up today & say, “I will not let the second casualty be my children.”

so it just got me wondering "how do ppl end up w nutso opinions like this?"

I mean I say its nutso and that's how it lands with me for sure but I really am trying to become the kind of person who naturally investigates the interests behind all sides of a dispute rather than getting stuck on my own knee-jerk reactions