It doesn't always go that way. Rashida Jones is black and white, but if she were cast as Misty Knight, I'm pretty sure there'd be objections.
At any rate, I'm not concerned with the technicality of it. If there was a girl who was only white but didn't look right as a redhead, I'd be against her being cast in the role, too.
True, but that's what they've been doing with Storm, and they've continuously ignored the outrage...
if characterization is more important, then Peter can be black, Asian, or Latino, Storm could be white or Asian or Latina, Captain America could be black, Asian, or Latina etc.
They could change the race but keep the characterizations of those characters intact. You could technically change the race of any character but keep the characterization the same, doesn't mean that would be the right decision.
With Peter Parker you'd be racebending, but that was generally what people on tumblr and twitter wanted if they couldn't have Miles, the personality of Peter would be intact, but his fans would be disgruntled.
With Storm, her parents are African-American and African, you can't go around that, her mom is a part of an African tribe, if she was white her culture and heritage would erased, her significance as an iconic black superhero would erased.
I know people then use the blue eyes and white hair as an excuse and to derail, but the continent of Africa is the most genetically diverse continent in the entire world. There are tribes of people with blue eyes and/or blonde hair. The white hair on Storm could easily be a birth mark or mutation.
Adding in Black Panther, Black Panther is African, and he's a part of a nation that hid itself, and isolated itself from the world. How can he be any other race than African.
Captain America is black, Sam Wilson is Captain America, b/c Captain America is a title and not Steve Rogers, and no you couldn't change Steve Rogers race, b/c his race and the time period he was from play a factor in him becoming Captain America.
So no you really can't change the race of every character.
Maybe Zendaya is playing the Vultress and she's actually the main villain
Would her being Vultress explain the chemistry test she did with Tom and not Keaton...
Also how can she be a main villain if her role will expand later, that would imply her role is small in this movie.
But I have no problem with Zendaya being Vultress.