In my opinion (and it is a weak one), is that in the 1980s, the future "seemed" so much farther away. For historical reference purposes, that was still in the time period when kids used encyclopedias to write book reports on typewriters. In the 80s, 2015 was the future Marty McFly traveled to and now we are less than a year away from a time that was looked upon as the future (still don't have my damn hoverboard though!) Ideas, history, art, etc…, seemed so much more out of reach because the outlets for them were very limited. EPCOT was an epic idea at the time because it was sold as a theme park where you could go learn about the world you live in.
I think for our generation - those that were or near teenage years in the 80s - the future seems more like everyday reality at times. Answers to questions that I have now are all achievable in the palm of my hand. iPhones, iPads, computers provide such a wealth of knowledge now that a desire to go somewhere to learn something seems unnecessary, and probably absurd to some. There are other things that people have now that were only seen in movies or read about in books in the 80s.
Because of some of the advances we have achieved, I truly feel that most people today don't want to go to a park to "learn" something. There is now an online society where people can learn whatever they want, whenever they want. Body Wars? Why pay $90 dollars to go into a park to learn about the human body when I can learn everything about it on my Android? I think that most people want to go to a park for mindless entertainment.
Now do I agree with that? No. I think that the idea that originally was EPCOT was a tremendous, truly challenging idea for a theme park. I actually prefer the term concept park for EPCOT. When I first went to EPCOT in 2009, I was blown away by the scope of it. However, after walking around World Showcase and back through Future World, I remember leaving and feeling that the park was rather disjointed. Also, it was sprawling but with not a lot to do. I have recently watched some Youtube videos about EPCOT in the 80s and saw the potential for that park, but I feel that WDW has given up on that challenge for the time being.
Could they resuscitate it? I suppose that they could but I feel that the lack of sponsorship for the pavilions and the extreme cost makes it very painful for them to consider. I also don't see things like Body Wars working with today's general populace. To me, it should be centered around space exploration, and not with a ride that nobody goes on (i.e., Mission Space). That is something that could still be educational to people because I believe that space exploration is still an ideal that entices almost everyone. Perhaps WDW should speak to the new wave of billionaires that are trying to start their own space travel companies. They might be willing to spend the money to breath life into the pavilions again. Hell, even deep sea exploration is something that I think people are fascinated by. Get James Cameron involved in the Living Seas and make a Journey to Titanic Ride where you travel to the bottom of the Atlantic (Bill Paxton needs money these days). There still are things that WDW could do with EPCOT, and people would love them for it.