Best I can tell it's an issue of philosophy. Many people in the US (my people, lucky me) are fearful and angry. We really seem to like our vengeance (consider the country music songs that were coming out post 9/11 as we entered Afghanistan and Iraq). When it comes to crime we don't bother with "rehabilitation". When it comes to mental health, that's clearly a lack of personal responsibility. If I can tell that they aren't really a knight in King Arthur's court on a holy quest, then they should be able to realize it too. Lock them up, throw away the key.