You are so correct. I am not here to forecast the death of Disney; I love WDW. But for the last 10-15 years we have been living in an era of dying institutions. You could not have said it better when mentioning Vegas casinos, Gimbal's, etc. Even the most beloved and iconic institutions that adopt a bean-counting survival mentality are endangered. This applies to just about any segment of our world you can think of: entertainment; retail; sports. religion; publishing; etc.
A company/institution trades on its goodwill for too long and it endangers its future. Here's hoping this is not a path Disney chooses.
I see Disney's franchises as completely timeless. The Disney animated movies for the past 50 years are classics - like Wizard Of Oz, Casablanca, etc. - and Disney has dozens of them. I don't see any of Disney's classics as "dying institutions." WDW can milk them for another 50 years and they'll still bring in the people.
The problem with WDW is that they aren't progressing fast enough with new attractions - regardless of what the franchise is. I used to work at a theme park in the Midwest. No matter what, we got a new addition every year - a MAJOR new addition every five years. Disney isn't even close to keeping up with that timetable. They seem to have been operating with that schedule for the whole resort, rather than each park.
You just can't wait five+ years to add something new to underdeveloped parks like DHS or AK! Especially in the current competitive market Dis finds themselves in now.
Disney has known that people will come anyway. Why spend money when the people will still come? I just hope they realize that those days are quickly coming to an end. The FLE is a very good first step. Unfortunately, because they've waited so long between new attractions, EVERY one of the parks is in need of the same kind of expansion (and no, adding a new restaurant to EPCOT or changing the movie on Star Tours is not going to do it).