Let's say I agree with that for the sake of argument.
Lut known as Lot in the Old Testament, is a prophet of God in the Quran. He also appears in the Bible, but the biblical stories of Lot are not entirely accepted within Islam. According to Islamic tradition, Lot lived in Ur and was the son of Haran and nephew of Abraham. He migrated with Abraham to Canaan. He was commissioned as a prophet to the cities of Sodom and Gomorrah. His story is used to demonstrate Islam's disapproval of rape and homosexuality. He was commanded by God to go to the land of Sodom and Gomorrah to preach to his people on monotheism and to stop them from their lustful and violent acts
So this means that he was telling them to stop. If they stopped, would he have told them get lost, God won't forgive you?
The sin is insisting on doing it. Repentance is always open as long as the person didn't die and the sun didn't rise from the west.
Almost all homosexuals have problems and they wish they can stop. They all have the fear that they would be left to grow up alone. And they aren't peace with themselves because they are doing something against human nature. They all want to live a normal life. Islam gives them this opportunity.
Islam doesn't just tell you do and don't. It offers you the way to do it. No soul is charged to what it can't take.
2:268
Allah does not charge a soul except [with that within] its capacity. It will have [the consequence of] what [good] it has gained, and it will bear [the consequence of] what [evil] it has earned. "Our Lord, do not impose blame upon us if we have forgotten or erred. Our Lord, and lay not upon us a burden like that which You laid upon those before us. Our Lord, and burden us not with that which we have no ability to bear. And pardon us; and forgive us; and have mercy upon us. You are our protector, so give us victory over the disbelieving people."