He's got great visual style but likes to please the studios too much, hence the disappointments. The director's cut of Kingdom of Heaven is a good example. That is one of his great movies, the theater version is terrible. Studio wanted him to cut, and he did. Losing one complete character which only motivated a shitlot other characters did.
I suspect Damon Lindeloff was brought along to Prometheus because the studio wanted him, and he's pretty much to blame with everything that's wrong with that picture. I've read the synopsis for the original screenplay and that was way better.