Pretty much what
Psab keel and
Axlotl said just above... Star Wars came along as a paean to simpler days, when the good guys and bad guys were clear and unambiguous. Before George read the Power of Myth or Hero With A Thousand Faces, he still knew basic fairy tale structures -- questing knights, the Arthur Legend, the Maiden in the Tower, slaying the dragon, etc,. Anyone who knows the originalest translations of Æsop or the Grimms knows there's some seriously dark **** in a lot of those fables, and there are echoes in even as bright and innocent a fairy tale as Star Wars was. Luke didn't just defy his uncle and leave -- the only family he'd ever known was killed and burned by the Empire. Leia was tortured by Vader and then Tarkin destroyed her entire planet as an object lesson and intimidation tactic. A subplot thread that was in until very late drafts of the script was Motti urging Tarkin to use the
Death Star to overthrow the Emperor and take over, himself.
Leaving aside issues I have with some of Campbell's more dated notions, or how he used such a broad brush in places as to render things almost meaningless... Yeah, George took things to darker, more symbolic places in Empire and Jedi after he decided to do more Star Wars. A lot of that was that he shared his ideas around a writers' round table with Leigh, Irv, Larry, and Richard, respectively. There was a lot of back and forth and refinement and he could reference some trope and the others would work it into decent story. But when George got to the Prequels, many balls were dropped.
Mainly, in forgetting what he'd laid out in his old notes and how that utterly changed the tone of the story, mixed up with being the solo scripter and his own (previously acknowledged) weakness in that area undercutting the presentation of the story elements he ended up going with, whether part of his actual original premise or changed. Obi-Wan was to be the focal character, and he's a much more straightforward hero than supposed-to-be-supporting-character-Anakin. That phase of th estory was more of a tale about how even always making the right choices is no guarantee you'll win. His arc ending on a down note, though, is okay, because it's not the end of the story...
...Just as Luke and his father defeating the Emperor wasn't the end, either. Leaving off right at the moment of Luke's apotheosis is bad narrative if the story is to continue. He needs to either ascend to a heavenly state (Heracles getting his mortal half burned away and taking his place as a god, Siddhartha achieving Nirvana, etc.) or come back to the ordinary world from his revelatory experience. As I've said before, it's fine for Our Heroes to have their victory erode from the returning impact
of that world's ordinary-ness. We just need to
see it. "Episode VII -- everything's gone to ****. Anyway, moving on..." is not really a narratively effective way to bridge the gap. Unless it's supposed to be a mystery we unravel along with the main character(s), which is not the case in the Sequels. Everyone seems to know what's going on except us.
