Hypothesis - I wonder if this is about places with lot of movement vs places that don't. Internal movement within US, even within rural communities, might be more than in Germany? and so, society tends to be more accepting of new incoming people?

From my observations about Germany and what I read about the USA, there was historically much less internal movement in Germany than in the USA. But over the last decades, shifts occured: internal movement increased in Germany and decreased in the USA.

> and so, society tends to be more accepting of new incoming people?

I would say the topic is more multilayered:

Traditionally, Germany was not an immigration country (yes, there exist exceptions in history: migrations of big groups from other countries, but let's ignore them for the sake of the argument), so there barely exist any traditionally grown structures for immigrants from other countries or cultures; they are much more on their own.

I wouldn't say that this bare existence of immigration structures is a bad thing per se, or that such people are unwelcome etc. It's just that there exist no really structured way for immigrants from other countries or cultures to set foot in Germany's society.

On the other hand, the increased internal movement over the last decades in Germany has not lead to the situation that incoming (German) people have an easier way to get into the existing structures, but I would rather say that this lead to a more tolerance of new incoming people doing their own thing separately.

In other words: it lead to the situation that people living next to each other often having few common things in their ways of living.

So, the increased internal movement rather lead to a loss of "common grounding" of people living in some place, without anything new appearing that replaces this loss of common grounding.