I think it's just one more of the cultural differences that exist in the world - a bank has made a TV campaign out of them. Interestingly, although we expect Americans to use and indeed not use words in the same context as the British, your point reminds me of an episode of the TV series 'Mork and Mindy', starring Robin Williams. Although a childrens' show, and aired in afternoon viewing time, they referred to a 'Mr W**ker' in one episode, much to the chortling and blushing amusement of the UK audience. The obvious absence of any laughter or sideling glances by the cast proved your point - to the Americans, it is just another surname. As for that island in The Shetlands - don't let's go there - at least not in conversation!