Most of the men in prison and in the old sailing ships at sea who had sex with other men were forcing their will on weaker men/boys in the absence of women. In the ancient world, this was the normal way. Unwanted children were regularly exposed in the streets and if they survived, they were enslaved or went wild. Many of them became prostitutes since the average Roman only wanted to satisfy his lust with whatever object was available. Families and marriage regularized this lust and channeled it toward reproduction. What distinguishes modern homosexuality is how organized it is, so that its members are able to create a parody of the family and to convince a large number of people that the arrangement has some social value.
And it was a reproductive strategy that worked wonderfully. We populated the planet. Civilization takes some of the bumps out of the road. Homosexuals can contribute to civilization; Michaelangelo certainly did.
What distinguishes modern homosexuality is how organized it is, so that its members are able to create a parody of the family and to convince a large number of people that the arrangement has some social value.
To what end? I don't think it's a conspiracy.