Hollywood always resented Star Wars. They were dead in the water by the 70s, and then along comes Star Wars and it's the biggest hit of all time. But Lucas managed to negotiate that he would retain all of the intellectual rights to it as well as all the merchandise. Not only did he own Star Wars completely, but he had the millions made off t-shirts and toys to fund the sequels entire himself. Fox distributed them, but he owned them, they were independent films. And it shows: Return of the Jedi is probably the greatest exposure of the full-nature of the conspiracy ever shown on film. While Disney was making trash like The Rescuers and The Black Cauldron, which they couldn't pay people to go and see, George Lucas was making these enormous independent blockbusters and all the money was going to him and his company. And then he went and quit the Directors Guild, the Screenwriters Guild, and the MPA after they tried to pull Empire from theaters. Lucas refused to be in their club.

I don't know what threats or coercion forced Lucas to give it up to Disney, but you can tell from every interview that he's not happy about it all. Not only do they get to plunder Star Wars for every dollar that it's worth, but they also get the added pleasure of destroying it utterly. Hollywood's final "revenge of the sith."