Is lack of gender/racial diversity valid criticism?

[Azuren]

I just don't like having characters' ethnicities changed for modern adaptions. For example, Johnny Storm in the most recent Fantastic Four train wreck. Why is he black and his sister is white?

Then there's basic Hollywood whitewashing and (more recently) Japanese yellowwashing. Yes, I'm call Japan out of that shit: all of the characters in both Fullmetal Alchemist and Attack on Titan are German/European... So why the fuck are they all played by Japanese people now?