I tried to get on board with the IP thing, but the problem is that they're sticking in IP at the expense of the educational aspect. Maelstrom was about the culture and folklore of Norway, whereas Frozen is just a random collection of scenes from the film (I finally got to see it for myself in January, and... I don't think that I'll bother again). The Living Seas (while I admit that the ride itself wasn't quite the main attraction of The Seas and could have done more to be interesting) was about seeing live sea life and how they're conserved and cared for in captivity, whereas Nemo & Friends actively hides that to show you popular scenes from the film. El Rio del Tiempo had a somewhat better fate, but Grand Fiesta Tour still downplays the aspect of showing off Mexico's culture more than I'd have liked (and suffers even more from being made during Disney's weird peekaboo "where is [titular character]?" phase).
My point is that all of these attractions that have been replaced by IP attractions definitely did need some updates and probably some reimagining in general, and, while the things that they got replaced with aren't amazing, I would have been alright with them if they weren't in EPCOT. None of the replacements actually addressed the problems that the rides were showing in the first place, and it's left EPCOT without any kind of theme whatsoever, particularly not the one that it started with that was educational while still being fun and hopeful for the future.
It also shows a broader problem across the Disney World parks - what I loved about it was that every park offered a vastly different experience, and gave me a specific reason to go to each one. Magic Kingdom had popcorn-length and very Disney-esque rides about fantastical things, EPCOT had a series of long dark rides made to educate you about a particular subject, MGM Studios had a bunch of tours and rides showing off the history of film and how it was currently made, and Animal Kingdom had actual live animal exhibits and areas realistically themed around different parts of the world. Now I feel like I can just go to Magic Kingdom and Animal Kingdom and get the full experience.
I do understand that the entire concept of EPCOT was very risky in general, and the sponsored pavilions model probably won't hold up, today, but I feel very strongly that there are ways to still keep to that theme today, and that giving up on it and defaulting to a cynical parade of "look at how great Disney is" isn't the answer. I won't get too much into it, but, to me, it just highlights a depressing problem with the shift in cultural attitudes over the last few decades.
(and I will entirely admit that I just really love dark rides and have always been a massive nerd, so there was never a more perfect park for me than EPCOT. There's nothing else in the world like it.)
I do apologise if I come across as depressing and cynical so much. This is just a subject that I feel very strongly about, and it's been eating at me, recently.