jomifi
Its all about context though - if you think about the major players in American film and television (New York and Los Angeles), it would be strange to see dramas that didn't[i feature prominent black and Hispanic roles, because these are very diverse cities.
Okay - there [i]exceptions] - I can't recall a single black face in any of Woody Allen's New York-based movies, but then, they are set in and around the Lower East Side and Greenwich Village so that's understandable.
Another difference I think should be highlighted is that until fairly recently, black actors in the UK were hired specifically to play black characters (if you see what I mean) whereas in America, there are many, many dramas where the fact that the actor playing the role is entirely incidental to the character (for instance, Homeland, Friends, House, Malcolm In The Middle...).