It's funny, because the bias has *always* been there in the enthusiast magazines (at least since I was subscribing in the early 1980s.)It seems that it is politically correct to slam anything American made or designed, while anything foreign is automatically deemed better.
American cars were big, crude, with archaic suspensions, and could not match the subtle refinement and fine, precision handling of the Euro/Asian crowd. Road and Track, in particular, was very good at running articles explaining how slower, more expensive cars were the future, American V-8s were dead, etc. etc.
It took 20 years for their attitudes to spread fully into the mainstream, but spread they have--and we now have a poisonous media culture with respect to domestic cars.