That's a rather philosophical question and I don't know that anyone could give you a definitive answer. My opinion, FWIW, is that your second question is closest to the mark. The American culture is more individualistic, which is going to make Americans more amenable to moving outside societal boundaries. I would further offer that our liberal friends have done their level best to eliminate personal responsibility and measurable consequences for making that choice, making it less personally costly for people to operate outside those bounds. The risk/reward balance is totally out of whack and it's predictable and expected that we'd be in the mess we're in.
Sweden is more independent than the US, yet with a much lower crimerate. It's also a country with a comparable soft justice system. American anthropologists in Sweden are usually surprised by how people behave. They place easily stealable stuff out in the open and you can spend an entire day downtown without spotting a police car.
Social psychology and sociology have presented quite a lot of data to answer the question how to reduce crime. Probability within populations is one of several ways the concept "free will" have been debunked.
This doesn't, as some suggest, makes the justice system invalid, to the contrary. the probability of crime where there's an existing justice system go down.
Law is only one way to prevent crime. Sweden have a branch of the government known as the Crime-Prevention Council that year after year apply the latest science on how crime works in order to reduce crimerate, reports that is then handed over with suggestions to the government on how to prevent future crimes.
Few people are psychologists, they usually use their own thought patterns and apply them on mankind as a whole. Trying to imagine someone elses behavior when one is safe, secure, stable and well rested can easily create the illusion that crime is rational.
Most crimes are irrational with no thoughts on the justice system whatever, they simply follow very predictable patterns, patterns that can be manipulated by external forces. The idea that crime is
calculated and a
choice is an unfortunate placeholder that reduces the will to implement effective crimeprevention systems that acts as such forces.
For established people, the strength of punishment is irrelevant. Their status depends on not being recognized as a criminal and the loss of social status, friends and honor. For irrational crimes, the strength of punishment is irrelevant since no calculation is done between risk/reward. The only one who do risk/reward calculations are people with some psychological disorders which are very few.
But social psychology can also explain why a culture insists on the issue still being in the justice system even though that justice system is already one of the harshest and largest in the western civilization.