How do you know these people have certain moral codes written in their hearts? Perhaps they don’t, and that’s why they are the way they are, or the codes are different than yours?
Its the natural law. Murder,rape,stealing-bad. It is what a republics law is based on. These things are universally identified as wrong and the reason all societies penalize them. We know there has to be an absolute right and therefore an absolute wrong otherwise we could not measure anything. There must be absolute beauty in order to know ugly, there must be a moral code to know sin. People “tweaking” codes is why there is so much strife and division in areas like social justice, abortion, marriage, etc...