Akechi

There are no rational arguments of course but humans are not generally rational. Gays are different than the majority and minority groups have always been oppressed. Religion came along and simply provides the pseudo rationality to justify the oppression.

There is the (pretty weak, imo) argument that anal sex has a higher risk of spreading disease.

There’s also the argument that if gay men are repressed, they are more likely to have children and pass on their (higher average intelligence) genes.

All in all, pretty weak arguments when put against equal/human rights.