Giving a role to a minority has increasingly come across as trying to fill a quota, which is just as racist as refusing a role to a minority. Giving the role to a minority based on skin color alone is in total disregard of their merits as an actor/actress and is racist.

http://time.com/4246183/jj-abrams-hiring-diversity/ -- intentionally increasing diversity for the sake of diversity, it's supposed to be a natural thing you do, not something you make a conscious effort toward.

It’s good for audiences and it’s good for the bottom line.

-- JJ Abrams

It's about money in the end.

Casting a white person in a minority role is just as bad (Tilda Swinton in Dr. Strange) is equal to casting Idris Elba as Roland Deschain -- it makes no sense. Where does 'Detta's racism toward Roland fit into the Elba playing the gunslinger? 'Detta wouldn't spew racism at someone like Elba. People are so afraid of the backlash they pretend to support it (looking at you Stephen King), or artificially increase diversity just to fill a quota.