I think the disappointment is in the general lack of innovation at WDW in the last 5 years. DLR got Cars Land, with a true E-ticket (even if largely a Test Track clone) in Radiator Springs Racers, a few more rides, and great theming. In that time, Universal's gotten WWoHP, Springfield, it's getting the WWoHP expansion this year, the Transformers ride, and probably a few things I've left out. WDW got...New Fantasyland and a few reskinnings of major rides (Star Tours 2, Test Track). New Fantasyland was supposed to be the answer to WWoHP, but it's at most comparable to Springfield, despite taking 3-4 years to finish.
And during all that time, WDW has been active, but it's all in ways to get people to spend more money. New hard ticket events (Harambe Nights), new small plate restaurants at Epcot. and of course MagicBands. And in the process, Disney is closing or ruining beloved attractions (Imagination, Wonders of Life, most of what made the Backlot Tour worth riding).
To answer the "well, just go to Universal!" complaint, I like Disney's properties and style better in general (though the Simpsons and HP are nice). Transformers may be the greatest dark ride of the decade, but it's still a Transformers ride

And it's even more frustrating to see the Animation Studio having a revival with Tangled, Wreck-it Ralph, and Frozen, while WDW's management seems to still not have learned the lessons of the original California Adventure. Revenge of the Mummy may be one of the best themed coasters in Orlando--where's Disney with a comparable ride themed to Tangled or Monsters, Inc.?