agreed. Seitz in that post, and in your review of The New World, i think you hit on a point that while seemingly obvious, often eludes most film fans (art fans in general, actually): there are more ways than one to truth in art. A film needn't have a 3-act structure, it needn't speak the language most are used to, and nor should actors or actresses need to fit particular roles in order to be deemed great.
I read a quotation the other day from Rob Reiner where when asked to act in a film he hadn't read the script for, he jokingly said (paraphrased), "Sure. After all if it's bad, it's not my fault, i'm just acting in it." To me that misses the point entirely.
Certainly a director plays a large part in whether or not the film is good, but I think the popular sentiment that the script makes the film is misleading if not often times downright wrong. Actors, in what they bring to the role, often times make or break films. Scripts can be great, and the acting god-awful and the film is just average.
Scripts can be very average, yet sparkle in the hands of certain actors (An example I recently came across was the film "New Waterford Girl"). More often than not that isn't because the actors didn't have the technical skills, but because they didn't have the charm, the sparkle, the presence, the instincts, the honest, almost naivete that allows the viewer to fall in love (after all, isn't that what art is aiming for?