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?
I guess using it as a polite euphemism for this kind of thing is valid
The brain breaking? Or the trying to stay?
Or the culture shock?