Eh, I think in most cases, the screenwriter is more important than the director. If you gave Aaron Sorkin's
Social Network script to a competent shooter like Brett Ratner, he probably would've made a good movie, albeit not as good as the one we got. (I think Ratner's
Red Dragon is pretty darn good, and it's almost certainly the best script he's directed.) But if David Fincher had been forced to make the
Last Stand shooting script, it would almost certainly still have been a bad movie. Of course, depending on when a director comes on, the structure and shape of the screenplay can be due in large part to their control, so it's not black-and-white, but I think the cinematic cult of the director is in many (though not all) cases overblown.
It's easy to blame Kinberg for
The Last Stand, and say that he should have dropped the Phoenix storyline
when Fox demanded the "Gifted" story feature also, and maybe he should have. But maybe he honestly tried and couldn't find a way to make the Gifted story be sufficiently compelling on its own. (After Xavier almost killed all humanity in
X2, after all, it's hard to argue that humans shouldn't have
some protection from mutantkind.) And maybe he
is a straight-up bad writer; I don't know. But I do know
The Last Stand was 11 years ago, and that he's worked a lot since then, so maybe he's improved...