There's been a bit of discussion about Tolkien's merits, or lack thereof, as a storyteller in this thread. One complaint that occasionally gets leveled at him is that he gets too focused on world-building, that he just vomits up huge masses of explanation about the incredibly detailed world of Middle Earth he's made. But any actual engagement with the text of The Lord of the Rings shows this to be pretty false. By the time he wrote it, he already had several decades of unpublished writings about the First Age under his belt, and had made several lengthy treatments of the 'Great Tales' of Beren & Luthien and the Children of Húrin (including some sadly unfinished versions in verse). But in The Lord of the Rings he shows frankly incredible restraint, just having Aragorn give the briefest summary of the tale of Beren & Luthien, and no more than name-dropping Túrin Turambar. Other stories from the First and Second Ages are treated similarly, only mentioned in passing with no in-depth explanation given. Again, considering that he actually had extremely in-depth explanations for many of these things, the amount of restraint he showed in not blabbing everything out about the awesome world he'd built is frankly amazing.
Similarly, while the 'Star Wars' universe is today famous for the great mass of obsessively documented details built into the EU, the OT, taken by itself, is very restrained and suggestive in its world-building. The 'Galactic Empire' has a 'Senate'? Once upon a time there was a 'Galactic Republic,' 'Jedi Knights,' and some 'Clone Wars'? The Jedi are followers of a 'hokey religion'? Etc., etc. Yes, all of these things have since been explained, but they weren't in those original films. They were just suggested and hinted it.
My point - aside from wanting to talk about Tolkien - is that this seems to be a mistake that was made in the Prequels, and even more so in the Sequels. They look at these incredibly successful stories that appeal to nerds, see that there's giant masses of autistic world-building there behind them, and think that what's appealing is the autistic world-building. So they shoot out huge wads of promotional details with the backstory of this background character or that alien race, make sure the drinks served at their tie-in theme park have a precise in-universe explanation, and so on. But it was never the details that captured the imagination in the classic, really popular stories. The stories came first, and the details only became known (or were made up) once the stories had already won over millions of fans.