You are right and the prison situation in the USA is not ok. But that said, just as this situation could be called f--ked up, also keep in mind that many parts of US society are also REALLY F--KED UP. There's a lot of injustice and racism throughout the criminal "justice" system, but there's also a sick amount of senseless, senseless violence.
Source: Friends and family who are prosecutors and public defenders. A relative of mine was once in the position of having to defend a group of teenagers who lynched and murdered a stranger on the street with golf clubs.
Maybe without agreeing, you can at least understand the motivation for [definitely short sighted] tough-on-crime programs.