Because the first game was just a disappointment, and the demo was just AWFUL.
The cover controls weren't all that responsive, the targeting system was only mediocre, and the camera, OH MY GOD, the fucking camera.
I know that they're trying to be "stylish", but if it interferes with making the game FUN, then the game is just sticking itself up its ass. Everything was all pixelated, so I couldn't see the enemies all that well, and sprinting was just god damn atrocious because it makes the camera shake like Cloverfield crossed with every single Paul Greengrass film ever made.
One weird thing was that when you headshot-ed someone, it would completely censor the bloke's head with pixels, which was kinda funny at first, but when you're always headshot-ing dudes, it became rather irritating, and strangely felt like they only did it because the ESRB or something like that wanted to give it an AO rating or ban the game or something stupid like that.
So yeah, no one is excited because the majority thinks that it sucks.