People of all ages have always loved Disney, but in the last decade the trend of the "Disney Adult" has grown tremendously. A "Disney Adult" isn't just an adult that enjoys Disney, but rather an adult that has made Disney, the brand, their entire lifestyle and personality. We see them everywhere now. They go to the parks "Disney-bounding" and gush over every single shoe-horned character insertion. They vlog about it. They become social media "influencers" entirely around it. They largely don't know and don't care about WDW's history and legacy, and applaud at classic, beloved stuff being removed in place of new, lazy IP insertions. They see the new characters on the Epcot parking lot signs and think "wow, so cute!" because thematic integrity doesn't matter to them, and they can't even comprehend why others would be upset about it. To them, Disney Parks = a celebration of Disney IP and nothing more.
The distinction between the Disney Adult and someone who simply loves quality theme parks and themed entertainment has to be made clear. I would wager that most of us on here are the latter. Enjoying Disney media alone does not make one a "Disney Adult", but even if you fully embrace that, you're likely here on WDWMAGIC because you also loved WDW for the unique, one-of-a-kind quality immersive experience it provided.
For most of WDW's existence, it was possible to have a WDW vacation without being constantly bombarded by Disney, the brand. Sure, the characters and IP were always there, but they weren't everywhere. There was always a balance. You could spend a week at WDW and see very little "Disney" stuff if you wanted. You could love WDW for everything it had to offer without being someone who cares about Disney, the brand, and their IP. This is, unfortunately, no longer the case, and the company is rapidly moving further and further away from that version of WDW.
The irony, is that for most of WDW's existence, WDW adult fans often had to justify their enthusiasm because WDW has never been good at marketing itself as a place with something for everyone in its advertising, always instead opting for shots of characters hugging kids and teacups and Dumbo. "Why do you like Disney World so much? Isn't it just for kids?" "Well no, actually, (massive list of awesome all-ages and even some adult-oriented things to do)." At which point that person could, if they cared enough, do some research into all that WDW actually offers and see that you were right.
But today, the opposite is true, WDW IS that version of itself it has always marketed, where you are bombarded with characters and IP at every step. The current version of WDW caters almost exclusively to kids and the Disney Adults who eat the branding up. Those of us who are simply lovers of theme parks and themed entertainment now have to justify that we like it, largely because of how it used to be, and not because of the Disney-brand fest that it now is.
So yeah. A Disney Adult and a fan of WDW/Disney Parks, while not exclusive, are not the same.