Then compare to other prison systems. In which case you will notice a fun correlation - the ones most successful in "rehabilitating" criminals are those that don't have particularly many nor particularly hardened criminals to deal with.Of course rehabilitation isn't some "universal cure to criminal problems"; but there is evidence to suggest it can work. The sad fact of the matter is though that it's rarely been tried, because our prison systems are designed more to exploit the free labor prisoners provide. They want people to stay criminals, and end up back in prison, because that's better for their bottom line.
The circumstances USA deals with are the opposite.
Which is a reasonable thing to do if the rehabilitation didn't happen, especially in case of violent criminals and thieves. Its not about their "debt to society", but reputation loss and even risk to the person making the decision.Couple that with the fact that most people just feel better seeing criminals punished forever, and refuse to associate with them even after they've paid their debt to society, and you have a system that ultimately incentives criminal activity just as much as it disincentives it.
The feature of your legal system is that *everything* is expensive. It is not a good feature.It's not a problem though, it's a feature of our legal system that executing someone is so expensive. Our system is built upon the premise that is it better to let ten guilty people go free, than for one innocent person to be punished for a crime they did not commit. People on death row are allowed so many chances to appeal, because we never want to find ourselves in a situation of executing an innocent person.
That comparison is more relevant to historical times than now, when a lot of nasty criminals weren't arrested on complicated, not completely conclusive evidence, but in the age of DNA tests, cameras everywhere, and criminals often recording their own crimes, increasingly often criminals are caught on unquestionable evidence of their guilt, and the legal process is all excuses, politics and technicalities about why they shouldn't get punished.