> If yes, we've established that governments and by extension their people have some right (even responsibility) to get angry about what people do behind closed bedrooms.

In these examples other people are actually negatively impacted. In the case of a couple being gay that's not the case. Perhaps if they are extremely loud about it, but this goes for all denominations.

> One of the critical functions of any society, human, insect, literally all animal societies, is to maintain replacement reproduction, or risk societal collapse. Furthermore, societies compete with other societies. It's a defensible argument that society should care about its reproductive issues, here represented by the closed bedroom.

That's a very medieval take. Our main challenges now are environmental and directly linked to overpopulation. Also, killing people that are gay (like many backward countries do) is not going to make them straight and reproduce.