There's a lot I could say about this (especially about everyone being on Miller's dikk without batting an eyelid after spitting on him years ago when he was set to do JL) but I'll just say this:
Miller is a man who would absolutely nail Superman. And not because he's a great action director, but because he strongly believes in a positive world view. Because in many of his movies, even in the violent, brutal Mad Max universe, there's a message that acting on compassion and kindness, to be willing to forgive and not punish, achieve greater results than giving in to selfish, defeatist motivations. And that is precisely what makes Superman Superman.