There's hundreds of years of art and literature you can delve into if you're genuinely interested in the idea, from Victor Hugo to Dostoyevsky to Arthur Miller. But I guess to me it boils down to this. Harming other people, even within the context of civil institutions is harmful to the soul. It creates abusive relationships that degrade the harmer and the harmee. When we institutionalize harm we separate ourselves from that degradation and make others bear it. Furthermore, that culture of harm is not static. It is capable of moving through our society and reaching indirectly all kinds of people. Our civilizational aspirations should take us away from revenge and towards grace and understanding.

But that's just like my opinion man.