I, personally, having made a bunch of movies (unfortunately not professional ones) can say that when I watch my own movies, I'm completely sick and tired of watching the same thing over and over. Because I know it so well, I usually just pay attention to the nitpicks and how terrible the quality is and how the angles aren't right, and how the actors mess up here and there, and how dumb everything is. The negative aspects... but that's because I usually do everything myself BUT, what I think is the case with George is that he is a fan of his own work. Otherwise he'd just leave it alone and not care after the first Star Wars came out. There obviously might have been different reasons, but considering how well made ESB and to some extent ROTJ turned out, It's a really really fun process to be just thinking up these various plots, ideas, and the like. I'm getting off topic. You know what? Forget it...
But I do know this: Since he is the originator of all this, he definetly holds a different "view" and "Feel" of this whole series than any of us. That's probably part of the reason he keeps changing things on the original Trilogy.