People say this to mean, “The code of moral rules and social etiquette that I picked up from my peer group in puberty is superior to the code that you acquired during your period of puberty.”
First, I encourage you to acknowledge that on a subjective relative scale, we’re all probably hitting our own moral targets pretty well with the same rate of success. Then, I ask you to acknowedge that on any absolute scale we can construct that is remotely reasonable, we’re all failing miserably.
If you do those two things, all of your hostility toward your neighbors should melt away. In particular, don’t evaluate their actions in terms of your subjective code, but do it from their code. In worldly values, their code probably has some pros and cons relative to your code, for success in this world. There were probably exemplary people from that culture over the decades or centuries who modeled that code put to the test.
Look, when a French guy walks up to me and says, “Comment allez- vous?” I don’t answer, “Huh? Where I come from, we would say, ‘How ya doing?'”
Last thing: I’m not engaging in moral relativism in this post. Rather, I’m saying you have no business judging anybody else if you use a subjective code. And if you try to use an objective code to judge others, guess what? You just judged yourself too, you hypocrite.