I think there's fan disappointment in any media -- books, movies, games. I remember vividly a number of fans who felt extremely disappointed by Star Wars Return of the Jedi because Han Solo's character was essentially "neutered" by the scriptwriters. It just happens... fans have expectations... and with those come a certain number of disappointments. Now, should we try and keep expectation in check? Sure.
As I said to begin the thread...
... I was very disappointed by the first few hours of dragon's Dogma II. I thought the beginning of that game was terrible, a severe disappointment, but as I've continued on, I've found that the problem was moreso a poor opening act than a bad game; I've now come to really enjoy Dragon's Dogma II... but that first act is still disappointing.