A bit hard to explain as most people don't really understand what a director (or a producer) actually does. They just think if a movie is good, it must have had a good director. If it's bad, vice versa.
And this is compounded by the fact that different directors take very different approaches to their jobs. Some, like James Cameron, are obsessive micro managers who, in full or in effect, also become producers, editors, writers, sound mixers, designers, and even FX guys on their own films. Some, like Michael Bay, have such extraordinarily large personalities/egos that their influence starts to leak into every aspect of the film even beyond film direction.
George is like that a bit, too, but IMO his biggest weakness as a director is his complete inability to direct convincing scenes of emotion between characters. He doesn't care about actors and doesn't know how to elicit good performances from them.
He's got other faults as a director but this is his biggest IMO. He's also the richest man in Hollywood and has surrounded himself seemingly with a bunch of sycophants and yes-men who don't question his dumb decisions. That's another problem.