So I don't disagree with your points. It's just part of a larger picture. My points probably don't even complete that picture.
But for now, for me, it boils down to: inequality + a culture of being civilized.
Culture has nothing to do with it, it's only inequalities. Look at the list of the 50 more dangerous cities in the world [0]. How come the US is the only developed country in the list with St. Louis, Baltimore, Detroit and New Orleans. All of those have a higher murder rate then Sao Paolo.
People might be scared of the SWAT, and brutal police, and incredibly long jail sentences. But when they lives in extreme misery, they feel it's worth the risk.
It's not very different from poor populations working dangerous jobs.
[0] https://en.wikipedia.org/wiki/List_of_cities_by_murder_rate
The inequality is partially cultural, e.g. when children don't even learn to read, which counts for some US city as well. Hence, criminal risk assessment seems rather informed by tradition and a myopic outlook (quite literally). So I agree that they "feel" it's worth the risk. On top of that, any local variance in potential will be deceived and abused. The problem then is that informing the deceived and stopping the abuse is hindered by exactly this lack of consciousness. Of course that's an issue of trust.
Error margins are huge either way, when the potential profit seems high and alternatives very low. "Nothing to lose" implies a zero division, resulting in an arbitrary decisions. So at least we can probably assume that for every criminal effort there are as many good intentions on the other side of the equation. Only if you look at people as numbers it's purely economical.
On the other hand, culturally, there are a lot of parallels to developed countries, too, e.g. in business culture. Then the overall difference is rather economic, which the developed countries profit from, thus increasing the differeyial. The US ie. is a more important market than the home countries for the drug cartels, or the weapons being produced in the developed countries).
Education is cultural and economic. It's hindered by poverty and stands counter to crime. Now, the education and the systems devised to control it are a different topic.
There is correlation of income equality and crime, but inequality is far from the only factor impacting murder rates, for instance.