Definitely agree with your points but maybe “dilutes”. Isn’t the right term. I don’t think they’re worried about their culture being “watered down” or “thinner”, but replaced.
I had a recent conversation with my brother that fits here. We grew up the same, but he became more conservative and moved to a conservative area, or maybe I became more liberal and moved to a liberal area. I’ve been exploring cooking, and actually this has been several conversations where I’m excited over learning about preparing a different cuisine, being able to appreciate what that brings, and he responds with “why can’t you make regular American food?” “Diluting” the cuisine we grew up with would be to use salsa instead of ketchup or mayo. But I have entire meals replaced with new and different. I have a much bigger spice cupboard full of new and different. I make meals that he doesn’t understand, doesn’t know how to prepare, so he gets defensive about what he is comfortable with being replaced