It's not just that "Uber" is a German word, but that it's a word associated with Nazis (via "Deutschland über Alles"). Another association is the Ubermensch:
> The term Übermensch was used frequently by Hitler and the Nazi regime to describe their idea of a biologically superior Aryan or Germanic master race;
> The term Übermensch was used frequently by Hitler and the Nazi regime to describe their idea of a biologically superior Aryan or Germanic master race;
https://en.wikipedia.org/wiki/%C3%9Cbermensch
When I first heard of Uber, it's what I immediately thought of.