The vast majority of people I personally know practice the family or what I call family type poly - the type where all of the paramours and metamours are expected to know one another and at least nominally get along. I dont mean family as in everyone has kids/lives together etc. I tend to be the exception to that rule in most of the relationships I am in as well.
Ive definitely asked everyone and gotten their answers which are very much along the lines of "because this is better" "why dont you do this" and they get very disheartened when I tell them why I dont. Ive seen too many explode and also because I am simply not interested in their paramours, metamours or families as more than other fairly nice people, but I have a lot going on. I didnt ask here because I cant talk to them. I asked here to hopefully get a larger sample.
My current metamour and her actual family unit practice the family poly thing and while I can entirely accept what they do as something I just dont do, I get tired of being odd person out even in poly conversation. I will say though this isnt the issue per se, I really am attempting to understand why people have an issue with it so I can more gracefully (?) And intelligently tell them to back off. Aside from the "back off. This is my way that is your way." Bcause that has led to alienation which isnt comfy for anyone.