Plus, speaking for myself here, I'm just tired of being expected to know all of these properties at this point.
Like, I have some Pixar films I like; over the years they've made some absolutely wonderful stuff, after all! But part of what creates a connection with a themed attraction is universality; I shouldn't have to know what a given movie is to enjoy something, but now there are so many new rides/areas based around films that if I haven't seen them or don't personally enjoy them, I'm not really interested in spending tons of time there. This is made worse by our modern "content is king" era where new sequels and whatnot are being pumped out endlessly; this isn't, say, the early/mid 90s where Disney would release something like Aladdin or Pocahontas, give it a parade at MGM Studios and a shoutout here or there in the park, and then do the same for the next movie, there's now pretty much an endless supply of content and it's filling up every available nook and cranny.
It's not to say every single IP-based attraction requires riders know everything about it, I've seen some that manage to sidestep it, but it's just getting more and more alienating at this point.
And ultimately, yes; why bother with different park names or aesthetics if the end goal is "keep dumping our properties wherever?" I think "Epic Universe" is an incredibly dumb name for a theme park, but part of why Universal's doing it is because EU has no overarching theme - each area is based around a specific property, that's it. The difference is, they're not, again, insulting our intelligence the way Disney keeps insisting on doing, by telling us Cars fits perfectly into Frontierland, or that "this is what Walt would have wanted; see, we built a statue of him prove it!", or some other nonsense.