So now Disney has a ton of extra hotel capacity and competition. People are going to Orlando (fewer of them, but they still go) and they say "we will spend four days at WDW, two at US, and one at SeaWorld - that's seven days" If they want to throw a day at the ocean in there, or a day at Cape Canaveral, they were giving up one of thier Disney days (who needs to see Epcot, sounds boring). And because they were only going to be at Disney about half the time, why stay on site.
Now Disney provides an "all inclusive" experience that encourages guests not to go to Universal. With Magical Express they don't need a car (which means they are stranded). And who can argue with dining on vacation for $40 a day! What a bargain! On site isn't THAT much more expensive at a Value.
You can see it in Universal's numbers - they are hurting. But Disney's theme park division is sitting pretty. And it appeals to the folks that want an all-inclusive experience.