the problem with the pre trilogy is that from the time of the original trilogy lucas became an icon therefore nobody wanted to challenge him creatively, the behind the scenes i full of arts where he says some obviously stupid idea and everyone around him just goes into a hundred mile stare
That, and it has been posited by "star wars scholars" that Lucas was a hungry young director who wanted to make a point, and then as of
RotJ he realized that he wanted to be a father. He has stated that he felt he'd been ignoring his kids, and wanted to be done with it. Changing from wookies to ewoks may have been less of a marketing decision, and simply the softening of Lucas' vision to make it safer for kids.
Arguably, it's this same "make it safe for kids" ethos that drove
The Phantom Menace away from the dark, cool, heroic epic of the original 1977
Star Wars movie and into what is, to a large extent, the comedic and dramatic equivalent of
Home Alone in Space.
