The thing everyone has to remember is that Lucas was creating a kids movie.
If this is the case, then why would George have been panicking that he made a kids movie just before the release of Star Wars? If that was his goal all along then he wouldn’t have been worried. First i remember George calling Star Wars a kids movie was after the prequels were slammed by fans.
I believe his concern had more to do with the G rating the film received, which by this time was seen as “uncool and a sort of box-office poison for a non-animated film.” The studio actually resubmitted the film and requested a PG rating. http://spinoff.comicbookresources.com/2014/08/27/movie-legends-revealed-did-star-wars-add-a-severed-arm-to-earn-a-pg-rating/
I recall Lucas saying in interviews both before and right after its premiere that his main target was young teenagers. And that was basically what some would call a “kids movie” back then. But we all know what happened…