Fairly standard in Polyamory 101-type guides is some sort of discussion about what reasons make for a good or a bad start to a non-monogamous relationship style. Such lists, written by experienced non-monogamists, often seem prudent to peruse, each item apparently self-evident in its validity.
Who could disagree that reluctantly engaging in multiple relationships because your partner wanted to when you weren’t really feeling it is a bad thing? After all, people should not do things they don’t want to do.
Who doesn’t agree with the idea that having an open relationship because your partner cannot fulfill all of your needs is a good thing? It sounds so much better to add more partners than to replace the one you have, if you love that person.
The problem with this sort of reasoning is that it represents a One True Path style of thinking that is relatively ironic given the relationship paradigms that non-monogamous folks claim to reject.