The Wizarding World of Harry Potter is probably the single biggest property that you can't find in a Disney theme park, but you could have. Disney actually was the first company to start talking to J.K. Rowling about creating attractions around Harry Potter, but it turns out that Disney's plans weren't nearly as grand as you might expect. According to theme park historian Jim Hill...
This was tiny. Itty bitty. There were two attractions. Basically, it was going to be Buzz Lightyear. You were going to be in an Omnimover attraction with a wand instead of a gun, and you were moving through basically a Dark Arts teaching class. The other aspect was going to be a Care of Magical Creatures Petting Zoo.
The idea, as described during Jim Hill Media's Universal Joint podcast, was that Harry Potter would only be given a "mini-land" that would be built in a corner of Fantasyland in the Magic Kingdom. The area would have the two attractions described above, and in addition would have a Leaky Cauldron quick serve food location, which one assumes would serve butterbeer. However, J.K. Rowling wasn't blown away by Disney's ideas, which led her to make a deal instead with Universal Studios theme parks, and the creation of the much more extensive Wizarding World of Harry Potter which now exists in three different theme parks around the world.
While the two attractions described may not be much, they certainly don't sound like bad ideas. Any ride that lets you swing a magic wand in the world of Harry Potter sounds like fun. An attraction similar to the current Buzz Lightyear attraction seems like an odd choice, but one imagines all sorts of dark things surrounding the vehicles that you could blast with a wand and that sounds great.
While the "petting zoo" attraction may also seem a little unlike Disney, Jim Hill explains that it would have contained animatronic magical creatures that guests could actually interact with, such as a hippogriff that would bow to you after you bowed to it. That seems pretty cool. Being able to interact with several of the magical creatures from the Harry Potter movies could have been a lot of fun, even if it was only a simple "petting zoo."
Of course, Disney's loss was Universal's gain in a big way. The Wizarding World of Harry Potter was built on a scale that Universal had never undertaken before. However, it has been a remarkable success and has clearly helped Universal compete with the massive mouse house that otherwise pretty much owns the theme park industry.
Universal treats the Wizarding World almost like it's a separate theme park and it seems like most guests do as well. Many seem to go to Universal Orlando really only to see the Harry Potter portion of the park. The rest is just a bonus.
Disney has gone through various periods in the history of their theme parks where they have tried to be frugal and it looks like the Harry Potter opportunity just came along during one of those points. Disney was already spending a lot of money for a massive upgrade of Fantasyland and probably simply didn't have the money to spend on an entirely new land dedicated to Harry Potter.
Of course, in the end, while Disney may not have been willing to spend a bunch of money on Harry Potter, Harry Potter still made Disney spend a bunch of money.
The popularity of the Wizarding World of Harry Potter pushed Walt Disney World to compete in a way they hadn't had to do previously. The loss of Harry Potter may have directly influenced the way that Disney has designed both the Pandora: The World of Avatar land at Disney's Animal Kingdom and the upcoming Star Wars Galaxy's Edge that will be part of both Walt Disney World and Disneyland. Clearly, money has been no object in these cases. Galaxy's Edge is the single largest -- and one assumes most expensive -- addition in the history of Disney Parks.
Both lands are much more immersive and complete than anything Disney had done recently. Pandora looks like you stepped off a spacecraft onto the alien planet and while nobody has experienced Batuu yet, every indication is that the new Star Wars land will create a level of guest immersion nobody has experienced before. Whether or not we'd see these lands at all, it seems a safe bet we wouldn't be seeing them in quite the way that we are if it weren't for Universal Studios raising the bar with Harry Potter.
Still, it makes one wonder just what would have happened had Disney won out on the Harry Potter deal. If J.K. Rowling had pushed Disney to do more and the theme park had built their own land on par with the Wizarding World we know, we might not have Pandora or Flight of Passage, the greatest theme park ride currently in existence.
By the same token, if Universal didn't have Harry Potter, the company would have needed to find another major franchise in order to compete with Disney. If they didn't have one, Universal would be in a very different place today.
One also wonders how a Disney/Harry Potter relationship would have worked in the long term. Disney isn't against putting properties in the parks that they don't own. Star Wars, Indiana Jones, and Avatar all started out as independent brands, but eventually, Disney took ownership of all of them. Disney made sure George Lucas knew the company was interested in Lucasfilm if the day ever came he wanted to sell. If that day ever came with J.K. Rowling with an existing relationship with Disney, it's not hard to guess Walt's company would be equally interested.
If nothing else, this entire exchange just goes to show how important competition is. Universal needed to make Harry Potter a special and unique land in order to compete with Disney, which in turn needed to invest in its own bigger showpieces in order to compete with Universal. In the end, the theme park guests are the big winners as we get to experience it all. The only thing we need now is enough vacation time to actually go to six different theme parks in Orlando on the same trip.