Monogamous humans should be able to function in their own societies, with their own laws and a culture adapted to the non-trivial differences in social behavior monogamy entails without having to put up with the predatory behavior of polygamous humans and the cultural propaganda to glorify it. It's been shown that for monogamy as a trait to continue to exist it needs to be the dominant behavior in a group of animals. Others are free to revel in the "joys" of dog-eat-dog polygamous primate societies as long as they engage in this with others who consent.
Also noone exists in a vacuum. One's actions affect others (directly or indirectly) particularly when they live in the same society. Having people with deeply conflicting standards of behavior coexist in a futile attempt at a one-size-fits-all society that inherently favors one group over the other is not going to work.