If you want me to give a real world example of anarchic (un)systems that flourished how about pirate communities in the Caribbean of course they flourished by the very kind of criminal behaviour described earlier.
I'm well aware of terrible nastiness of even the most benign governments. Especially when there territorial control of sovereignty is involved. Small crimes tend to affect people personally and are still oppressive. I grew up in poverty(first-world poverty nothing onerous) and I know first-hand that rational self interest is usually not only not likely to be employed but also actively frowned upon by the criminal underclass. Nor does a criminal underclass rely on voluntary transactions and their idea of a good reputation is one of ruthless viciousness to outsiders anyway.