"Do you think incest and polygamy will be legalized?" - Part 7

I came across a poll on the subject of the future of full marriage equality:

I was watching a TV show recently and surprisingly, three characters (two men and a woman) got together in a sexual AND romantic relationship - as in, it wasn’t just a kink, they were serious about it, they even made their relationship official to their family/friends. And it got me thinking, do you guys think polygamy will ever be legalized? And incest? And should they be, and if not, why? Will our society ever see it as acceptable/normal like with gay relationships?

Closing statements:

I don’t understand why y'all feel so comfortable trashing these people, and arguing for legally abusing them. Is it because y'all don’t know them personally? Well, I do, and they’re perfectly nice, reasonable people. Actually, some of them are nicer than the “normal” people I’ve met. They love one another. They take care of their kids. They pay taxes. Emotionally, I don’t understand how people can hate that so much. Trust me, just because you don’t think you know such a couple, doesn’t mean you don’t. The closet for both [polyamorous and consanguinamorous people] is large, and the closet for consanguineous couples is massive. It doesn’t mean they like living in fear and secrecy, and they shouldn’t have to. However, it’s easy enough for them to get away with it that they don’t risk rocking the boat.

It seems like what y'all want is to shove them into the closet and tell them to shut up, so y'all don’t have to be confronted with personal discomfort. Why should your personal discomfort have any relevance to law in a liberal country which enshrines protections for the rights of minorities against the tyranny of the majority? How does shaming people and telling them to shut up encourage abuse victims to come forward? And more importantly, how can you demand such a contract when it isn’t in good faith? These couples do hide in the closet. The problem is that when other people find out accidentally, they hunt them down and throw them in jail, even if they hid it well.
They need to fight these laws, because there is never any guarantee that the law won’t be used to abuse them, regardless of how they behave. The majority always loves telling minorities to shut up and go away when they complain. Meanwhile, minorities complain because, regardless of their silence and isolation, the majority still abuses some from time to time to make an example of them. There’s no other way for them to protect themselves, other than to fight the legal and social regime.

Most feel like the cost of fighting is too high, which is why it takes decades of momentum to get more to come out of the closet. That doesn’t mean they stay in the closet because they acquiesce to this “agreement”. They’re just afraid. They’re afraid of y'all. They’re adults with otherwise normal lives, who’ve done nothing to anyone that could ever be construed as harmful or destructive. Yet y'all have the power to utterly destroy them. Is that just? Are y'all really comfortable being potential threats to perfectly nice people, some of whom y'all may know? I don’t want to be a threat. I don’t think anyone should have the right to be - not towards good people like them.