I think that there is an aspect of being seen to “not be playing by the rules” as well as the moral aspect. In one discussion I was in with a hater, he was going in that direction. I asked him why my husband and I have to have relationship parameters that were created by other people. If it works for us and makes us both happy, why can’t we have a marriage that we have co-created? There’s no cheating if it’s all consensual and open.
I write a lot about the social hierarchy aspects of patriarchy and how we have a whole culture based in dominating others (not just between men and women). Besides describing the problems with this (all social ills stem from this mindset) I’ve also been writing about some of the alternatives, like what a more partnership-oriented society would be like.
I get huge push-back and outright anger from men around that sometimes. They cannot conceive of a time when it wasn’t a dog-eat-dog setup, with violence as a natural component of that. It breaks their brains to hear that is only 10K years old. I think the same goes for polyamory. Some people can only look at relationships through the lens of one type of system, and to imagine that a totally different one is even possible — they just can’t go there. If you try to look at poly through a traditional lens, it looks dysfunctional. Meanwhile, it’s got many, many qualities that even monogamists would do well to bring into their relationships.