The people before us, starting from the Paleolithic era, strived simply to carry on their genes (more of their looks and characteristics, since they had no idea about genes) and their tribe. Their main focus in life was the continuation of their peoples, and their ways of life.
This can be seen throughout history with artistic expressions such as the Venus of Willendorf
Another, older (at least compared to the Paleolithic peoples), example would be in Roman times with the Goddess Venus
These three feminine figures share one common trait, they are all the ideal woman or the ideal woman for fertility and carrying on the tribe in their respective cultures. In the latter two, they were even made into Goddesses to represent this fertility and to show the women what the most feminine and fertile woman looks like.
This ideology of disliking non-fertile (especially consensually) is not limited to just the religious, but religion in modern times has almost taken the place of the tribe. The tribe still exists all around us with our fellow tribesmen and women, but the effects of it have been somewhat lost as we spread across the region, nations, and even the globe. Religion serves to unite people, similar to a tribe in the days of old, and share that guided message of keeping the tribe strong together, and to keep it reproducing.
Once we have established the sole purpose of the tribe, and that religion is a nearly global quasi-tribe, we can see why homosexuals were and will (and should) be disliked and shunned.
The majority of homosexuals in our current state are weak, reproductionless, degenerates*. The majority offer nothing to the tribe, religion, or even society in some aspects. Of course there are some exceptions, people like Peter Thiel and Tim Cook come to mind. They do not reproduce, contribute to society in a physical way, but in our current system they contribute with their minds… but they are the exception not the rule.
In the Paleolithic era up to the 1940s when people started easing off of hunting and physically working for their food, homosexuals still contributed to society. They were looked at less than a woman or a man though. This is due to them being able to hunt, like a man, but failing to reproduce which would pit them lower than both genders.** They were the weakest of the tribe, and the weakest of the religion, by failing to help it carry on. For this reason they were discriminated against and this is why it persists today.
If homosexuality is a neurological issue, and it is impossible to alter, non-homosexuals shouldn’t be interested in conversion. We should be trying to change their culture to go back to those pre-1940 gay men and women, who while they were still on the bottom rung of society, they were at least contributing and helping their tribe in one way or another.
**Most of the times the people did not admit to homosexuality, because it could lead to violence. They would just never have kids, and have relationships in private with other closeted homosexuals. Societies back then looked down on people for not having children, which would pinpoint the hate directly on them.