It is also a myth that all people in a poly family interact sexually with each other. Poly doesn't mean threesomes, it means a group of people that work together as a unit or family. Love isn't required for a monogamous D/s relationship and is not required for everyone in a poly family. I served a dominant couple for many years and was only property of the male dominant and only served him sexually. I didn't have sex or think about having it with the others. That is not what I was expected to do. That is why people communicate expectations before getting involved.
People often make sweeping generalizations they can't prove when they don't understand something. You should check out www.lovingmore.com and gain some insight before making judgments that you have not basis or facts of. Yes absolutes and one true wayism ways of thinking usually do piss me off. Poly isn't everyone running around being sexual with everyone else in the family. It isn't threesomes and sharing. it is a family unit that sets their own standards for what it is that is expected by all family members involved.
Poly isn't for everyone and those that don't understand shouldn't make falsehoods about those that live just because they really don't understand it. There are more myths about poly than the actual truth. Everyone has the ability to make their own choice about how they want to live their lives.