This prefix uber-
, particularly rampant
, is directly derived from the word Übermensch
, originally conceived by Friedrich Nietzsche
, and popularized by the German Nazi
regime, for whom it served to indicate the supposedly superior White
, which, by virtue of its superiority, supposedly had the moral right to enslave and mass murder people of different ethnic origin.
(Note that über- as a prefix is not in general use in German. Its use is quite specific to the particular word, Übermensch.)
As a direct and - apparently - approving reference to racism, the prefix uber- is quite offensive to Europeans of older generations, considered in bad taste, and viewed as a sign of the lack of historic awareness among American youth.
Compare the (hypothetical) use of a prefix nigger- in German to indicate 'bad', 'of poor quality'. (Note: this is purely hypothetical! German does not use any such prefix as far as I'm aware. It used to have a prefix Juden- to indicate 'treacherous', 'untrustworthy', but that was before the war.)
Know your language.