Good point. I definitely wouldn't trust that poll if it was claiming to predict the outcome of an election. I think the difference in this context is it would matter to me who the one or two people are. If they are close friends that I know pretty well, then I feel like I could make a positive judgment about them. If they are some random person in the neighborhood that I don't really know anything about apart from gossip, then I wouldn't trust myself to make that judgment without more information. I think the main problem with DC's anecdote is that the real issue there is poverty. A family that doesn't believe in contraception and has 10 children will have similar problems, but not many people are advocating for limits on the amount of children a family can have, despite the apparent detrimental effects it might have.
Let's back up here for a second.
The title of the OP is "Opinion of the Polyamorous community", not "should polygamy be banned". Plenty of people think poorly of people who have three spouses or ten kids. There's no inconsistency there. The level of 'proof' needed to support your case is a sliding scale. Thinking something is a bad idea requires significantly less support than putting your preferences into law.
Secondly, I want to bring up part of my anecdote that keeps being ignored. My primary issue with my acquaintance's polygamist parents wasn't financial, it was emotional. Recall, that I noted that the children were used as pawns in the wives' bickering.
Plenty of us have lived in households with financial strain. I doubt any of us have gotten punished because their mother was ten years younger and was having more sex with Dad than the other wives.
I agree that it's important to make the distinction between polyamorous and polygamist (but to be fair, your anecdote was a polygamous one afaik
). Probably one of the reasons why it can be difficult to assess is it's not entirely clear what a polyamorous relationship means. I think it can vary from couple to couple based on what they are comfortable with. Like all relationships, some work out, and some don't. Of course it's entirely possible for a marriage to be polyamorous without being polygamous if a married couple decide to carry on having a sexual relationship with another partner without actually marrying them. If that's the case, it's not likely to pose the same sort of challenges as a poly-marriage because people aren't living in the same house and don't share the same obligations.
I also think it's very important to point out that a polyamorous relationship
does not have to be permanent. A lot of people seem to be getting hung up on this issue. The relationship can be ended at any time, and ending it doesn't necessarily mean ending the relationship between two of the partners. The hallmark of polyamorous relationships is truly one of communication between all of the partners. If someone is really as emotionally distraught or torn up about it as people are suggesting, they can always work out their feelings with their partner and decide not to do it anymore. If they truly love one another, they'll be able to get through it.
Poly-marriage, on the other hand, poses a unique set of issues, both legal and emotional, like you point out. It also can't be ended as easily because it would have to go through divorce and possibly child custody disputes, if applicable. It definitely opens up a whole new kettle of fish. Despite that, it can also have it's benefits in that expands the number of people in the family. It's not like there aren't already non-traditional households. For example, there might be a married couple with an aunt, uncle, or grandparent also living there longterm. That's not really so different from having 3 "parents" - it's just that people have different titles. More people contributing to the family can have a lot of benefits. If anyone's watched "Full House," that's a good example of what I mean.
Anyway, I'm not in a poly-relationship myself, but I have some friends that are. I guess my main point as it relates to this thread is they are not horrible people. Quite the opposite, but the reason has nothing to do with their relationship status. They're human beings just like anyone else, and you wouldn't even know they're polyamorous if they didn't tell you.