C969 Wealth Comes from Danger
This is the fundamental, there is nothing worth explaining. I'm stronger than you by killing your entire family, no one will say anything, it's just a moral issue, after all, in this world, no law is the law.
If you dare to refuse to accept this and say that you will kill people to repay their debt, then it would simply be laughing your teeth off. Revenge is a matter of course