Interesting. Sounds like a counter-point to Hanlon's razor: "Never attribute to malice that which is adequately explained by stupidity".
I use Hanlon's quite a bit to explain nonsense I see day to day, but this is a better one in some ways. It shift the conclusion of "but if only they were shown the right way" to "they know what they are doing and are looking out for number 1".
Hanlons razor is about motive and "size of mental models". Stupidly small, or comprehensively large.
This other thing you note seems to be about scale being low or high. Individually fine-grained, or collectively coarse-grained.
I suspect mistaking either dimension can result in grossly misinterpreting a situation.
The lowest, most fine-grained level of individual self-interest looks a lot collective stupidity and failure to meet the collective's interests.
Democracy supposely recalibrates from these mismatches. But so do more drastic and unruly options, when democracy has failed.
Now I wonder if depending on the scale, one model is better suited. Or maybe they both can be modified based on the scale.
Maybe self-interest is easier to reason about than the interests of a group. Conflicting self-interests can lead to compromises that result in what looks stupid in the end.
- Someone harming you because they expressly desire to harm you? Unlikely
- Someone harming you because they are stupid and don't realize what they are doing? Maybe.
- Someone harming you as a side-effect of pursuing their own selfish interests? Most likely.