Even if that wasnt the case , the director should always be evaluated by the whole product , not just the visual aspect. Off course he deserves to be called out for Prometheus. He's the director !! His involvement goes way beyond framing and lighting.
Ture, but Ridley seems to be one of those directors who need a proper script to ground them, as opposed to molding a bad script to make a decent film. Give him mediocre scripts like Robin Hood or Body of Lies and he makes mildly pretty mediocre films, give him a decent script, he makes a mildly pretty decent movie like Gladiator or Black Hawk Down, give him a good script and he makes a good film like Kingdom of Heaven. What do you think of Kingdom of Heaven (directors cut of course), by the way?