There was also an interesting point about the curse of having too much money. With no pressure from a publisher or from outside investors to ship, they were relatively free to keep blowing deadlines.
These examples might also be due to collaborative pressure.
On Star Wars, Lucas worked with a great editor who could say no to him. Same for script on Empire. For the Star Wars films 1-3 Lucas had total control over everything.
Put another way: It's commercial pressure that made Lucas subject to collaboration. And it's subsequent commercial pressure that made collaborators subject to Lucas.
