Everybody grew up among, and got their culture from, lots of different kinds of people. You are right about the culture of Massachusetts, where I live. It’s a special place, but it’s a counterexample to your point. MA has one of the highest rates of foreign-born population in the country, and it has been that way for a long time. When I was growing up, there was a big influx of people from China. Today it’s India. A couple of generations ago, Italy/Ireland/Poland. “Eat to live, don’t live to eat” my mother told me, but her mom was born in Germany and her dad was Irish. Massachusetts — by the way also consistently one of the most Catholic states — shows you can have the Puritan culture without the Puritans.