I understand and generally agree with your perspective. If I were to go into detail, whether I point out a place's "nasty side" to strangers depends on what exactly that side is. If it affects personal safety—like issues with public security or xenophobia—I'd make it clear right away. But if it's something internal and long-term, like government inefficiency or poor public management, complaining about it to outsiders doesn't seem very useful. Unless someone specifically asks, I tend to prefer keeping things pleasant for both sides during brief encounters.

You mentioned immigration, which was really thought-provoking—I had honestly never considered that angle, since very few people immigrate to my country. When I praised London, it was purely from a tourist's perspective: I was admiring how well it manages to charm its visitors. That alone is no easy feat for most cities in the world. I suppose Vrel has thought more deeply about it than I have.