I really think you're underestimating the popularity of Star Wars, not for the first time either. I'd love a Pride Lands area or a Villains attraction but announcing those would not have gotten anywhere near the attention and publicity that anything to do with Star Wars has and will.
I really don't disagree with your overall argument, I have loved Disney, particularly animation and the parks, for as long as I can remember and I do agree that Disney doesn't need to buy IP's to fill the parks;I have zero interest in anything to do with Avatar and nothing will change that. But the relationship between Disney and Star Wars is not a new thing, its spanned decades and the creations of George Lucas, Star Wars and Indiana Jones, have inspired some of the most popular Disney attractions at their theme parks all around the world.
If I wasn't a Star Wars fan maybe I'd be more inclined to agree with you, maybe I'm biased. But considering Disney have a film-themed park in the midst of an identity crisis, a park that already has a very popular Star Wars attraction, and the biggest film franchise in history now completely at their disposal this really does seem about as much of a no-brainer as you could get. I don't see how it would be a better fit at Universal bearing in mind that this is the furthering of a relationship that has lasted nearly thirty years, you only have to look at the popularity of the Star Wars Weekends to see that the films and characters have become an indelible part of DHS in that time.