I too, am a little annoyed by this. Not out of racial hatred or anything, but for both historical accuracy, and for the BBC's obsessive Political Correctness quotas.
As others have said, I would have no problem with Black people/ other ethnic minorities playing fictional Shakespeare characters from the Comedies and Tragedies, I.e Romeo and Juliet, Prospero, Ariel and Caliban from The Tempest etc. But in a Shakespeare HISTORY, where, in the time period in England, the character is obviously going to be white, the BBC's Political Correctness does bug me.
Again, in the same way, there would be a moral/ political outrage if a White person were to play Martin Luther King, a black slave, or Shaka Zulu for example. The BBC would NEVER cast a White person for the role of Othello, in the same vein. Even though Othello is a fictional Shakespeare tragedy, it is clearly stated, by Shakespeare himself, that he is meant to be Black. The discrimination he suffers is the whole point of the story.
Cue the accusations of racial hatred...