What's wrong with trying to keep the film closer to the source material?
That would be fine, but it's not really what's being done for two reasons:
1) Hypocrisy. The same people complaining about "whitewashing" usually consider it to be a
good thing to have anyone who isn't "white" playing a character who is "white" in the source material. Hermione from the Harry Potter stories comes to mind as an example. And yes, she was explicitly described that way in the books, i.e. the source material. Pale-skinned even for someone who is "white".
2) It's not really about the keeping the film closer to the source material anyway. It's only about "race". It doesn't matter if the person doesn't look like the character in the source material or doesn't sound like them. Using makeup to make a "white" actor look like a "not white" character in the source material would attract a fury of condemnation, but it wouldn't attract any if it was about keeping the film closer to the source material. If it was about keeping the film closer to the source material, all that would be relevant is that the actor playing the character looked like the character while playing the character. Actors often wear make-up while working - it's a common part of the job.
For example, I'd have no issue with a "black" actor playing, say, Winston Churchill, as long as they were made up to look at least quite like Winston Churchill while filming. Or a "white" actor playing, say, Martin Luther King on the same basis. Because my position is that its generally better to keep closer to the source material, not that "race" is of paramount importance and not that racist hypocrisy is a good thing.
well exactly, people just have double standards when it comes to these things, there are black actors in Shakespeare productions too for example, no one really minds about that but cast a white guy in a film about say ancient Egypt and you get outrage, ironically often from African Americans with some bizarre notation that they're the true descendants of the Egyptians rather than the light brown skinned people living there today.
It's also worth bearing in mind that in Egypt at the time the film was set most of the people being portrayed were descendents of Greeks and would therefore have quite pale skin. That was particularly true of the royal family, which was so much into the "royal bloodline" thing that they usually married their own siblings.