Especially your point about "groupthink": the next big thing will always be great to them, and people who have made a stinker or two will always stink. Your winner or loser status is woven into your DNA to these people.

Are you "cool" or "not"? These things are generally decided by publicity pre-release, and non-professional critics or quasi-professional bloggers are wildly susceptible to this publicity. Now, so are some of the big name critics-- they're not exempt. Peter Travers, I'm looking at you. But they'll still have moments of integrity and unpredictability, whereas I can set my clock to what the Rotten Tomatoes score of a given film will be weeks before it opens due to knowing how the blog masses will respond.

They tend to value directors and the auteur theory more than stars, writers, or the general conceit of the film. Which is why you see folks shit all over folks like Nic Cage most of the time and ignore his great films, but you see people ignore or make excuses for the disappointments of the majority of their favorite directors.

This is only disappointing because critical response has a MUCH bigger impact on the population than most people would have you believe. Sure, some movies are critic-proof, but if a movie like Broken City opened to a 75+ on Rotten Tomatoes, it would've made more money opening weekend and had more legs.

I've beaten up on bad films before. It's easy and can be fun. But there's waaaaaaay too much mistaking disappointment for low quality. See: tons of people naming Cloud Atlas the worst film of the year last year. That's "hipster criticism" as you put it at its finest. Taking something big and ambitious and earnest and shitting on it for not being cool enough.