Any system is fallible. Is the person in prison because the courts worked or they didn't? Is the inmate in solitary because prison monitoring worked or it didn't?

So human sortings will never be 100% fair and correct.

But there's also a vast range to how people conduct themselves in the world and their moral codes.

I think it at least behooves us to consider that the greatest threat to rehabilitation of some inmates might be... other inmates.