People make judgments all the time. That's human nature. People judge things based on what they see no matter how much or how little. That's also human nature. People decide whether or not they want to see a movie from previews or pictures alone. They've been doing that for 100 years. This is no different and it's unfair to treat it as if it is.
I think it's interesting: Look forward to the movie less than 100%, be even remotely critical, and you must be silly and ridiculous. Look forward to the movie at all, and you must worship the ground JJ Abrams walks in. It must be great for people to think in such binary terms. Makes it so much easier doesn't it?
This is just like the ENT forum of old without shipping and less warnings. Too bad. Nothing's changed. It's exactly the same as 2001. It's nice to know that at least in the real world people decided yesterday they don't want to live as if it were eight years ago anymore.