For people who move to a foreign country (and it's usually a ~ cosmopolitan~ city at that) and then eventually move back citing "cultural differences" - like what differences are that stark that you can't live with them? Oh no the people there grew up with different stories than I did how can we get along? I'm i being too "I'm built different"? Is it a dog whistle for racism? What's up with it?
Eh, depends quite a bit. I knew Americans that moved to Germany and came back due to "cultural differences". It seemed that some members of the family didn't want to learn a new language and along with more minor differences.