You don't sound like much of a student of history.
If you had studied history, you'd realize that human society seems to constantly go back and forth on social issues. In the case of homosexuality, if you look at 4000 years of data, you'll find it oscillates between being ok and taboo. Its a neverending fickleness. I have to assume it depends on who controls the media and what agenda they have. The media is a VERY powerful tool and can be used to convince the masses of anything. It can be used to convince people homosexuality is ok, but it can also teach people to hate homosexuals. If the people who control the media decide demagoging homosexuals will advance their agenda, that's what they will do and the hate will take hold. And you'd be surprised how FAST hate can spread.
One thing to understand is that there NEVER is social progress. Its an endless cycle going back and forth, like humanity is stuck in a rut. You probably think that we've made social progress by accepting homosexuality, but history says in 300 years, social rules will swing back the other way and it will be taboo again.