There is nothing about the system that is rehabilitative. It will always be up to the individual whether or not someone rehabs themselves. Think about it, you bunch of savages together in a cage, starve them, provoke them, keep them in that environment for years, then release them, and then expect them to behave normally?
When there is a fight, the guards do nothing. They wait until someone is dead or beaten to a bloody pulp. Then any remaining person or party of people is sent to the SHU and an investigation begins. But of course, no one talks, because then you are a snitch and have truly sealed your fate.
You should see what the weight pile on a prison yard feels like, the tension. It's crazy. I once spoke about this with Thibs, I tossed out the idea that one of the reasons why guys get so jacked while inside is not from the food or the workouts. My theory was the increased testosterone from the threat of violence. You can literally feel it, you never walk the yard alone, especially if you go to a place that is considered gladiator school. I can only imagine what guys coming back from combat in the Middle East must feel like, getting shot at, and being locked up is by no means a decent comparison. But the threat of violence is fucking insane.