Yeah because white people never get a break in holywood...
I want to make it clear that I don't want to offend anybody and that I am decidedly not racist. However, I think the above argument has no place in casting decisions. If JB says Harry is brown haired we're not gonna cast him as a blond...it just doesn't make sense since their are plenty of brown-haired actors who would do a terrific job. And in a Buffy movie remake would we cast Spike as a guy with black hair? Or a Hispanic or an African-American? Would we cast Susan as a blue-eyed blond?
You say "white people never get a break in Hollywood," but the fact is that actors of all ethnicities have plenty of work to find in Hollywood for all kinds of roles.
And I would be equally opposed to seeing say, Jensen Ackles, play Will Smith's role in a remake of MIB. Yes, I think Ackles has the acting skill and style that would fit quite well but the fact still remains that he doesn't have the right look for the part. To me, saying you shouldn't consider ethnicity for a role is like saying you should cast a woman of average appearance to play Aphrodite in some movie about Greek myth. She may have all the acting skill in the world but she just doesn't match.
And as for the racist or result of racism (i.e. blacks weren't allowed to act) practice of face painting, I don't think that applies to discussions of current movie casting practices. And Nick Fury was changed to a black actor in the movies...Will Smith isn't the only black actor getting cast in roles written for a white actor. Plus there's the new Karate Kid.
Anyway, I just had to get all that off my chest. I hope no one was offended by what I said and I assure you that no offence was intended.