its got nothing to do with the thread going downhil when nazis are introduced.
funny thing that science fiction often mirrors life.
the eugenics program was widely embraced by the west as well, yes even *gasp* in America !
its just easier to shit on German's and hold up their regime as evil, but the prinicple is as old as 'civilisation' itself. when u think about it, more effort and fore--thought is put into breeding beef than humans.
the german example is just more well-known, and again prone to intermittent re-embellishment, cos well, being on the loosing side in history does that.
examples of eugenics in america is by no means obscure however, just type in "american eugenics program" in google.