Japan is not a multicultural country. The United States has ALWAYS been a multicultural country. From African slaves, to Native Americans, to the people who can trace their ancestry to the Spanish settlements. And, as KevanG pointed out... Why is it ok for Jay Garrick to give way to Barry Allen who gives way to Wally West, but this causes all sorts of hackles to be raised?
And yes, as a kid you look at the fictional heroes of the culture from a wide variety of genres and it does smart that "what" you are is rarely represented. I don't like to play this card at all. Really. And I know it's gonna sound smug as hell, but it's the truth as I see it... If you are not a minority, especially one that is culture-ized fully into the American mainstream, it's probably something you won't understand.