I'll start by pointing out I feel that the prison system is incredibly in humane and we need serious prison reform to a large degree. But I think there needs to be some understanding that there isn't a one size fits all solution, on one end you have a kid of a crack addict who gets in with the wrong crowd and ends up getting busted for being involved in an armed robbery because his buddy asked for "help" with something. Is the proper solution to throw the book at this kid and put him away for 20-30 years? Probably not.
On the flip side you have serial killers like Ted Bundy or the BTK killer, those people don't need rehabilitation they're simply monsters and deviants that need to be removed from society forever.
Any discussion that fails to acknowledge both of these groups exist is probabaly fallacious.