But not everyone believes in the Bible.
Homosexual behavior is obviously contrary to Natural as well as Biblical Law. Decent people in all centuries and all continents and cultures have been against perverse sex. Even the pagan Roman dramatists satirized it.
There are those who do not believe in the bible who see homosexual behavior as detrimental to society. There are those who say they believe in the Bible who are agnostic toward homosexuality.
My point is that viewing homosexual behavior as being detrimental to society is not limited to bible believers.