In any case, it's a clear sign of bias to single out race as the deal-breaking difference while being fine with changes in height or hair color or nationality or whatever. It's an indefensible double standard to say that turning Jimmy Olsen from a redhead to a brunet is fine but changing him from white to black is a "change of character."
Everyone does this when there's a charge of whitewashing/racebending. Does that statement only work in one direction? Or when one likes the change?
It does seem to create a double standard: It's okay to complain about casting Benedict Cumberbatch as Khan, but not okay to complain about casting Laurence Fishburne as Perry White.
As Christopher pointed out, that there is a precedent of white actors getting cast in roles over POC actors.
While I don't want to rehash the "white" Khan thing again. I will point to two other infamous racebending castings in Hollywood movies. Johnny Depp as Tonto (a white actor portraying a Native American) in The Lone Ranger and the casting in M. Night Shymalan's The Last Airbender.
There are Native American actors who could've portrayed the role of Tonto but Disney went with Depp because they wanted to use him to sell their movie. Depp still met with Comanche peoples and learned their language for the role but it was a tad intensive that Disney didn't try to find a Native American for the role.
With Shamaylan, he really stepped in it. The main cast of Avatar the Last Airbender is comprised of 2 characters who have Chinese distinction (Aang and Toph) and 2 characters who are Inuit/Eskimo (Katara and Sokka). While only 3 of the 4 appeared in Shamaylan's movie, all three were portrayed by white actors. The Inuit tribe was comprised of white actors, and no, there was no makeup applied to make them look ethnic. When Shamaylan was called out for this he said that he cast each actor based on talent and not race. He then followed through making other members of each distinct tribe/group reflect the actor's ethnicity. Although there was a bit of a controversy in to how the actress who played Katara got the role. HOWEVER, he said at the time (2010) that for the then planned sequel that he would cast Toph (the one of the 2 chinese characters) with an Asian actress.
Once again, the castings decisions made by a director and studio came off as insensitive. They had the opportunity to be faithful to the source material and content but purposefully neglected to do so.
With the roles that seem to be getting people rustled nowaday. Heimdal in Thor
Perry White in Man of Steel
Johnny Storm in Fant4stic (lol couldn't resist)
Aquaman in Dawn of Justice
These castings seem inspired rather than insensitive. Like they know the canon is there but there have been scores of adaptions before hand, so let's try something new. Also none of the aforementioned casting have anything to do with the race of the character. Heimdal isn't ruined because a non-white actor is playing him. Perry White's history of being a newspaper EIC wasn't betrayed by Lawrence Fishburne portraying him. Can't speak for Michael B. Jordan yet however, Chris Evans (or current Captain America) played Johnny Storm not 10 years ago and that didn't elevate either of the FF movies above schlock. So why not take a chance on a new adaptation? The same can be said for Mamoa as Aquaman. This is Snyder's vision for his Justice League. Let's see what he does with it.