I’ve noticed while traveling that a lot of places are not as racially/ethnically diverse as the USA. (At least the coastal parts of the US) Japan, for instance, only has 2.3% of its population made up of foreign residents.
People tend to think other societies are like their own, so if you are somewhere without much racial/ethnic diversity, this may play a role.
Amsterdam on a weekday seemed pretty seedy. The crowd seemed to get less seedy, but more rowdy on the weekend.