This is not even good conservative exegesis of the passage.
Homosexuality is, by definition, a condition where a person is attracted solely or primarily to others of the same gender. This is not the same thing as same-gender sex, because that can be done even by heterosexuals, e.g. commonly in prisons. Indeed the most explicit treatment of it in the Bible — the Sodom story — shows it as being threatened by people who are not homosexual (since it’s the whole population) and who clearly were using it as a show of dominance. Using sex for that purpose is not as uncommon as it should be.
First, there’s no sign that the Bible deals with homosexuality at all. The laws in Lev are about same-gender sex. The claim in this passage is that it is a result of idolatry, not “sinful lifestyles.” Because of their idolatry, God allowed their thinking and morals to become confused, and they gave up their natural intercourse for unnatural. The giving up natural part indicates that the people involved are not seen as homosexual.
The cause is idolatry (worship of images) and it looks very much like God actually caused them to be confused and turn to same-gender sex, as a punishment. That’s not actually an impossible understanding, since 1st Cent Jews thought same-gender sex was so obviously a bad thing that it is conceivable it could be a punishment. (I’m depending here upon Gagnon’s explanation of 1st Cent attitudes. He is hardly a fan of accepting homosexuality.)