The problem with Lucas is he needs someone like a Gary Kurtz to say "George, that doesn't work." Unfortunately, Lucas seems to not want people around who aren't yes-men. He clashed with Kurtz over the direction of Jedi, how the films were becoming more commercial and toy friendly, the tone of the film, and the cost of Empire and so he and Lucas fell out. Between that and McCallum never saying "no" and everyone who shows any backbone seem to be shown the door, Lucas has no brake. It's why we end up with stuff like Jar Jar and Red Tails and Crystal Skull. He just needs people he can rely on to tell him he's in the wrong, but he doesn't want them around.