As a counter to your opening point - it certainly helped me. It made me feel safer and I had a sense of justice. Not saying it's the same for everyone or that it's necessarily a good thing but the punishment of the person committing the act helped me to move on.
1. restitution (where possible)
2. removal of criminals from society so they cannot continue to harm others
3. re-integration of such people back into society when they are no longer a threat