Think about it: if I set you the challenge of "come up with a regulation model for this fishery" the nature of your solutions will be fundamentally different than if I set you the challenge of "prevent selfishness and greed from overriding the cultural, social and historical patterns for this resource use". Depending on your own particular political outlook, it is possible that given the first problem you would still focus more on the type of problem described in the second but that's not inevitable at all.
> There are no structures and never were.
Chinese overfishing ... when I look this up, the most common word associated with it is "illegal". Perhaps you mean the overfishing they carried out in their own waters before increasing (and now decreasing) the size of their distant fishing fleet(s).
> But you're claiming that people in country #5 are "willfully ignoring the social structures in place" and that's false.
In reading up a bit more about this (with China being country #5), I come across articles with titles like "China’s IUU Fishing Fleet: ariah of the World’s Oceans". So I don't think it's false at all.
> But you're ignoring it's also a justification for regulation and cooperation.
That's not an unfair point, but what I'm really getting at (mostly based on Ostrum's work) is that regulation and cooperation have always existed historically, and telling the story of ToC-style problems as if they haven't bends the solutions in ways that do not reflect the history.