I think people are also counting Jimmy Fallon as a disappointment.
Also, the general usage of screenz since Potter's opening, including Kong, Gringotts, Despicable Me, and the above mentioned Fallon.
Also, the general hate on Volcano Bay... some people have strong opinions against Tapu Tapu and virtual lines, as well as the over-hype / let-down of it being a "water theme park."
Also, the disappointment (primarily from die hard Universal fans) of Universal closing older attractions including Terminator, Disaster, Jaws, Twister, Dueling Dragons, and Beetlejuice (since Potter).
I'm not saying I agree with the disappointment, but it shouldn't be ignored.
My personal disappointment is that Universal is not pulling the trigger on Pokemon, Zelda, and other potential major expansions, and is possibly holding back due to FW.