The socially accepted norm and idea that homosexuality or any other sexuality that did not involve heterosexuality was a dominant mentality that stayed for generations and ironically, there were some eras in history where homosexuality or LGBT sexuality was not really treated with contempt and disgust like in ancient Greece.

Despite the recent yet slow change and awareness of this mentality and slow acceptance of LGBTQIA rights among many people around the world (and not just by people who were already familiar that being gay and not-hetero was not a deviant behaviour), homophobia still exists in some regard and even held strongly in some countries.

My question is how this mentality originated and how this has been shared and supported generally for many generations and also among many different cultures regardless of their religions/beliefs, nationalities, philosophies and so on