I think a lot has to do with our focus in the US on retributive justice (punishment) rather than restorative justice (rehabilitation). Our prisons do nothing to reform society, they serve to keep punitive systems in place for the disenfranchised. Many people don't open their eyes to the discrimination involved in determining who actually ends up serving time in prison, but rather focus on seeing prisoners being punished (thus, we hear statements like "It shouldn't be a country club."). Too many people fall into the "law and order solution" rather than look at the root causes of injustice that lead certain people to prison sentiences while others escape with a slap on the hand. Our prison systems thus continue to promote leaders who promote violent punishment, as though that type of cruelty is somehow necessary for "law and order". It's sick and disheartening.