I feel the same way, but NOT because it was a bad movie. But more like because had anticipated for so fucking long, I thought the day it got made, people just would not shut up about it.
And instead, people shut up about it fairly quickly. Same thing with Samurai Jack. And now ZIM is getting a finale movie and I feel like that fanbase is going to slowly wither awhile since they'll get a conclusion.
I guess the hope of something being uncancelled is more memorable than the thing actually being uncancelled, IE: Futurama, Arrested Development..