Alternatively while Nemo is far from perfect I'd argue that "filler" rides with high capacity, low lines, appeal to kids, eat crowds, aren't a big draw themselves, are good even if not great, and make use of underutilized spaces without cutting much if anything of substance are exactly what Disney needs more of. The fact that Epcot has rides like Nemo or 3 Cabs is exactly why it tends to be the most pleasant park to visit.
Sure I'd love an expanded experience, but there's not space to do much more. And even with Nemo not being the most popular, I can't imagine "the thing that they got rid of for being unpopular but now with less of a story" being a bigger draw.
Parks need relatively cheap filler B/C-Tickets to round out there line up and keep the park from feeling overcrowded. Epcot gets that. Which is why aside from Imagination (and I'd say Spaceship Earth is seeming pretty rough and could use good long refurb if not a new version) is the only thing there that really needs it. DAK and Studios need a good mix of new high capacity draws AND they desperately need low budget but still pretty decent filler like Nemo