One thing that kills me about prisons is that they achieve exactly the opposite of what they are supposed to be achieving. They add more psychological trauma, they create more anger and they force people to focus on what they've done in the past instead of what they could be doing different in the future.
The problem is that there are always more important things to worry about in our society than reforming prisons. Not much has changed since prisons have been invented, really. Recidivism is unacceptably high. The solution is not more discipline. It's more respect, more compassion, more dignity, more learning, and more showing that life doing other things is as rewarding if not more than doing the things that lead to prison.