I'm not sure King's tweet is really in disagreement with your argument at all. He's not denying the existence of unconscious bias; he's simply saying that a *work* of art is either good, or it's not, regardless of who produced it.

That's a quite different issue from the question of whether artistic *industries* are equitable, and indeed King also said: "The most important thing we can do as artists and creative people is make sure everyone has the same fair shot."

In other words, judge the industry (to some extent) by its diversity and openness, but don't judge the *work* on that basis.