It's a little bit different to that, in all fairness.
I think if we are talking about MN as a "society" we need to be very careful about discounting people's lived experiences because they don't suit a particular narrative - so when children who grow up in a polyamorous environment say wasn't a particularly nice environment to grow up in for them, I don't think we need to speculate that was primarily due to external social factors or that if not, it was an isolated situation.
Polyamory may work very well for some people and some families and be absolutely free of emotional load, jealousy, coercion, difficulty for those people. Maybe this may even be true of many, or the majority. However, there are a lot of people who have been part of this subculture who would attest that there can be significant emotional issues that arise and aren't always easy to iron out (see this link, which is nuanced but perhaps illustrates that it's not as straightforward an equality issue as it can be made out to be on fora like these).
My own parents had a brief "go" at what my father hoped was going to be polyamory but really was nothing of the sort. My memories of this involved a horrible Christmas Eve where his hoped for OSO (actually OW) came for dinner while my mother cried over the garlic bread. There was apparently a year of "negotiation" during which my mother was being counselled by the PARISH PRIEST (that's how far off engaging in polyamory her lifestyle was) to LTB, while my father came home sharing his glow and love while my mother worked out what the fuck she was going to do with her life.
Of course this isn't everyone's experience... but it isn't "ah I didn't see my dad as he was away, but then lots of dads do work". It was specific to my father's belief he "loved" two women while actually being a total dickhead and bringing one of them to the brink. It was utterly, utterly selfish and abusive.
I've followed this blogger for a long time and I think this particular entry is very insightful. There definitely is potential in all subcultures for abuse to flourish and it does no one any good to adopt this idea that it is wrong or phobic or pearl-clutching to question practices that appear to be harmful in some situations just because it may not apply to others: medium.com/@thelolaphoenix/why-i-don-t-identify-as-poly-71a5a541dc99#.2d8egmq9v