You're partly correct - people are getting more desparate and hopeless because their prospects are grim, and nihilistic because they feel their lives have no me

You're partly correct - people are getting more desparate and hopeless because their prospects are grim, and nihilistic because they feel their lives have no meaning. That's a problem and crime will continue to get worse as these feelings pervade American society. But also, we need to arrest and prosecute criminals, because not doing so encourages crime. It accelerates the downward spiral.