John Carter pretty much proved to me that Disney can make a competent, big-budget sci-fi action adventure.
Seriously, did you see that movie? It was rad.
Unfortunately, it also proved that they have no idea how to market such a thing... and seeing Disney, of all companies, fail at marketing is just bizarre. I left John Carter wanting to buy fully-articulated Thark action figures and a big plush Woola, but such things were never even made. I mean, c'mon.
Lucasfilm, on the other hand, is great at pushing the Star Wars brand. And, when George Lucas isn't writing, they put out some fantastic stuff. Lucas has, for most of his career, been a brilliant idea man--so long as he handed those ideas over to better writers--and had a great eye for talent. Unfortunately, he began to believe the hype about himself being a creative genius, nobody would say "No" to him, and everything went to shit.
I don't know if the Disney/Lucasfilm buy will change things for the better, but at least it will change things... so improvement is at least an option. Hell, even spiraling into catastrophic destruction would be more interesting than stagnation.