they really don't see the difference between homosexuality, a preference with no procreative value, and heterosexuality, which literally continues the species

Of course. Sex is recreational to them so anything that would get in the way of their recreation is an annoyance at best. (hence their views on everything from abortion to whether it's OK to not want to have sex with various types of people.) It's "just" a way to have fun with someone else after all. No more meaning to it than there's meaning in getting a drink of water.