Disney paid a lot for the Star Wars franchise, and i've read articles claiming that they could have gotten a better return on investment putting the money elsewhere.
I think the claim was that each movie had to make over a billion dollars to be a financial success, and 400 million was no where near what they needed to make to recoup their investment in the franchise.
Obviously Disney thought something was wrong, because they've put a hold on other productions, and they were sniffing up JJ Abrams tree.
Those reports would be ignoring the secondary market. SW is way more than just moves. The first Force Friday when they released all the new toys before the first Disney SW movie hauled in a billion dollars right there. Books. TV shows. Comics. DVDs. Disney was probably in the black on that deal before their second movie came out.
Disney paid 4 billion in cash and stock for Lucas. Six years later, the movies have made about that much. They paid the same thing for Marvel in 2009, and they paid 7.5 billion for Pixar in 2006. Those are both seen as brilliant moves, despite the fact that "The Good Dinosaur" only made 300 million and the first Captain America movie only made 176 million. One underperforming movie does not doom a franchise.