When did Indy roll his eyes at Lucas on Young Indy? And if this movie so horrible, as it must be because you've seen the film, why would Ford agree to star in it? Why not just say, "George, this film doesn't live up to the previous ones, let's give it a rest.'' Why would Spielberg? They didn't have to make it. They weren't destitude and strapped for cash. They didn't have to make this film, and I don't think they'd settle for just any crappy film out there. If they did, we would've had Indiana Jones and the Monkey King rather than Indiana Jones and the Last Crusade. They're doing it for the fans, people like us.
That in itself sets it apart from the Star Wars prequels, which were made because Lucas wanted to develop the backstory to Star Wars on screen; a completely self-indulgent work over which Lucas had complete creative control. Different story with Indy 4.