First of all, in the old days, if you wanted to show someone getting shot on film, all you could do was place an effect in the original take. And if you wanted to brighten somebody's face and leave the rest of the room dark, that was a very expensive process.
There are so many factors when you think of your own films. You think of the people you worked on it with, and somehow forget the movie. You can't forgive the movie for a long time. It takes a few years to look at it with any objectivity and forgive its flaws.