Why criticise a film?

A.O. Scott, one of my favourite movie critics, evaluates the role of a movie critic in a recent essay in the New York Times. In the light of the spectacular success of movies like Pirates of the Caribbean: Dead Man's Chest and Da Vinci Code despite extremely poor reviews, Scott says that critcs and audiences are finding themselves on the opposite ends of a bridge. The audiences want to have fun, and the critcs "go sniffing for art".
"...my colleagues and I must face a frequently — and not always politely — asked question: What is wrong with you people? I will, for now, suppress the impulse to turn the question on the moviegoing public, which persists in paying good money to see bad movies that I see free."
He says that critics don't influence the public's taste for movies as much the Hollywood studios do.
"So why review them? Why not let the market do its work, let the audience have its fun and occupy ourselves with the arcana — the art — we critics ostensibly prefer? The obvious answer is that art, or at least the kind of pleasure, wonder and surprise we associate with art, often pops out of commerce, and we want to be around to celebrate when it does and to complain when it doesn’t. But the deeper answer is that our love of movies is sometimes expressed as a mistrust of the people who make and sell them, and even of the people who see them. We take entertainment very seriously, which is to say that we don’t go to the movies for fun. Or for money. We do it for you."
Read the entire essay here.