I think the prequels should never have been made. As Red Letter Media pointed out, they were made just for money and because George "thought it would be neat". George used to tell stories because he felt he had something to say that was important.
Star Wars was made (in part) because THX failed; it told essentially the same story and had the same themes. Lucas felt it just might cause people to take action instead of just depressing them (like THX did).