Over and over everybody calls our prisons a failure. Prisons demonstrably fail to rehabilitate the inmates. But the prisons survive. Prisons survive because they are doing exactly what we pretend we don't want them to do. We unspokenly want prisons to punish people.
Prisons are extremely successful at punishing people.
They do not fail at that. But in a so-called civilized society we don't want to admit that this is why we have prisons. At our core, we know that shutting anybody up as a solution is barbaric. All we have to do is look at a dog in a pet shop to know this. But it's embarrassing to admit it.