Wright, you mean. I'd assume he was able, just uninterested. And good for him. I'd rather watch his vision than whatever corporate mandates ended up on screen.
Marvel actually have a pretty long reputation of hiring niche directors for their films. If not niche, than inspired choices. It's worked really well for them, I'm surprised they let Edgar go.
And Luke Cage, everybody saw Shaun of the Dead. We get it, you don't like Edgar Wright. It's fine.