It really depends. I have noticed this same trend recently, whereby things are accepted in other cultures because judging it would be "cultural imperialism". It even got into some previously non-controversial (in liberal circles) topics, like female genital mutilation. Google for "FGM cultural imperialism" for a lot on this.
Most people in the US seem to be far more tolerant of circumcision than FGM. And under many definitions, circumcision qualifies as genital mutilation...
