I think Edutainment is a good word. I don't ever recall it being just 'entertainment' though and I've been going regularly since it opened. I loved the Edutainment of it all and honestly I think the issue is that when the sponsors got harder, they tried less. They closed things without replacing or they watered down to a pathetic level.
It was awesome for many years, now while we love it, it's not as great as it used to be. Not everything has to be complete entertainment though. Many museums and such do wonderful without it being just entertainment. I think it's a sad reflection on society if people need it all the time. Not everything educational is boring.
It wasn't, but, it was still supposed to be entertaining to the point that you didn't know you were being educated. That was where it all failed for many. I agree not only is educational not necessarily boring you have to want to be educated before it becomes something you want. In my opinion, when EPCOT opened Disney really were convinced that they could make serious education interesting to the masses. They were able to convince a few of us that it was true, but, there were more of the people that didn't feel that way and quickly caught on the 45 minute lectures like the Universe of Energy was indeed not real entertaining and very much educational not to mention biased.
Museums have different expectations then a Disney Theme Park. Many of us really enjoyed it. However, it wasn't all of us. Even myself... I really didn't like UoE (aka.. Exxon commercial) and even though the first part of Imagination was over the top great, it became a look at your watch and want the end to get here quicker, type experience for me. Horizons was good (except the ending which was a good idea just not well executed) and to me had no can't wait to see it again factor. WoM was funny little romp though the history of transportation, very entertaining and fun to see over and over until either the public or GM wanted something more exciting. (probably a combo of the two, I would think). Spaceship Earth has always been my favorite since the beginning, but, I am at a loss to see where the "fall off the cliff re-entry" was anything but a snooze fest designed to make you forget that you were going really steeply downhill, backwards. The city scape and the song "Tomorrows Child were the two highlights of the trip back down to earth.
Seas, when it finally got there had a big challenge and that was to make an aquarium something other then fish swimming around. They did a fine job of creating the atmosphere by the use of the Omni ride... much shorter back then. It mostly went through the middle of the aquarium in a plastic tube (still does it's just that Nemo is blocking all the real animal views now). You could see sharks swimming right overhead. The Hydrolators were a fantastic addition that actually made you feel like you were descending into the depths of the ocean. Realistic enough that someone once tried to sue Disney because they moved downward to fast and they had some ear problem because of it. Don't remember the exact details, but, it was very funny and in all likelihood a totally alternate fact story.
So even though there is nothing wrong with edutainment, it wasn't accepted as widely as was needed to support EPCOT along with the fact the technology started (right after opening) advancing so fast that Disney would not be able to keep up with it in stationary show scenes.