It’s not just a casual matter of culture. It is a commandment of their religion. Deuteronomy 7:16 says that they must *completely consume* all the nations they get control of, *without pity* and reminds them to think of Pharaoh (the first innocent goy they scammed) if they get second thoughts about dispossessing you. Deuteronomy 6:10-11 says they get to enjoy “the cities they did not build, the houses they did not fill.” That’s what they believe they get as a reward for following their covenant: all the goyim’s stuff, after they’ve killed off all the goys. These aren’t remote verses, they are immediately adjacent to the *Shema Yisrael*, the prayer they say every day.