I think that's the point. The PC crows are the ones making an issue of it. Rush is just rubbing salt in it. It's what he does, he's a professional.
Except in this case, the PC people are not the ones making a big deal about this. A Sony exec suggested Elba for the role, without saying anything about his race - just that he should be the next Bond. It was Rush who made this an issue, and Rush who brought race into the discussion.