You go to a sit down resteraunt once a week, which maybe is not the most uncommon for families who are doing well. Going to the same Disney themed venue priced restaurant once a week, is not very likely. The average family of four, at least in their early years are not likely eating out at a costlier sit down restaurant once a week. And the same one, even less likely.
Applebees, Olive Garden or Golden Corral are not equivalent to Disney's prices so families would probably not eat there as often as their saturday meal out.
Most(but all need the parks and resort to maintain their level of success) of Disney's themed restaurants compliment the park and resort experience, standing alone they would be rough.
Its not the worst idea and I am sure the company still tosses it around, but its not likely worth it to them for reasons stated.
If the concept was viable, you would see more Rainforest Cafe's and others popping up, not closing.
The pop ups have novelty. And they can extend runs due to things working in their favor with the venue. But by nature, they are novel. That animation exhibit would not likely to do well without serious investment in a year, two or three from now. They make more having the pop up pack up and pop up somewhere else, and maybe come back to your area next year or in a few. Museums figured this out long ago and why local museums change exhibits.
