[SauronOfMordor]

This means that a good, practicing Jewish man is not permitted to engage in homosexual acts, but a Jewish woman can still be a lesbian (the Talmud frowns upon it, and calls it "licentiousness", but it is not prohibited by G-d). Likewise, a non-Jewish man can be a homosexual, and G-d makes no mention of it being wrong.

One reason why permitting homosexuality is damaging, is that gay men pair off with other gay men, and do not form families or produce offspring. Given a sufficient amount of social disapproval, it is possible to make a bisexual man, or even a man who is primarily oriented toward gayness, to orient toward women as his sexual outlet, and thus focus his energy toward family, offspring, and creating the next generation

Lesbianism was less of a societal problem. Women, for the most part, had little choice except to be married off, and sexually satisfy their husband and bear his children. As long as they were good wives and mothers, it didn't matter that much if they had a little fun with their "girlfriends" on the side

[MrsKentTrappedInLiberalSeattle]

One reason why permitting homosexuality is damaging, is that gay men pair off with other gay men, and do not form families or produce offspring.

Lesbianism was less of a societal problem.

All true, but not relevant to why G-d would ban such behavior. He said why He banned it right there in Leviticus, and producing offspring was not it. Yes, that does contradict the "be fruitful and multiply" commandment, but not having children is just regrettable, hardly a sin, and certainly not forbidden, so it can't be used as justification for forbidding homosexuality (especially since only male homosexuality was forbidden).