The German family gets a good amount of subsidies from the company to stay here in the US, so I think that has to be one of the primary factors in them deciding to stay.
The difference is in how protected they are from downside risk. You can even price it if you want: how much would it cost to buy a level of income and health protection in the US equivalent to the German safety net? Germany by the way isn't that generous by Western European standards. I'd be interested to see someone price it - my suspicion is that it would be ruinously expensive.
Of course, German nationals have the option of returning if they have to. They can earn in the US if their life circumstances make that possible while fleeing to safety if required. It's a pretty valuable option.
Like pretension? Portland calling here. Like Theatre? NYC calling. Like the cold? Alaska on the line. Like surfing? Hawaii here. Like the great outdoors? Pick one of a million places.
You just can't do that in any individual countries in Europe, as they are all smaller than most US states, with far less varied environments.