Problem is Lucas thinks having ideas is something rare. There's very little about Star Wars as an ensemble of ideas that made it great, rather it's how everything came together that made it great, and most of that was a result of each individual departments/directors/actors.
Lucas had the most control on RotJ and the prequels (the one who had the most control on ANH was time and budget
), and whether you like those movies or not they give you a much better idea of what Lucas is as a creative person and as a director, and RotJ wasn't even directed by him and it shows because there's still really good character moments (something ANH kind of lacks really if it wasn't for Ford). The original Star Wars scripts are pretty much just like the prequels, with all the emphasis on moments and concepts and bad dialogue.
The original characters would have never been as memorable if he hadn't received a lot of help in improving the scripts. Having Han shooting someone in a bar is meaningless, what matters was each line, his character, and that kind of character came from serious rewrites and the actors themselves.
When Lucas got complete control, we saw the result. It doesn't matter how Lucas thinks the story should go, there's a myriad of potential ways the story could go, what matters is how it's handled, and if Lucas had still been in charge as he would certainly have been if he hadn't sold to Disney (if there were any new episodes at all) all indications are it would have resulted in movies with the same serious flaws as the ones he directed before.