their opinions known. Critic is an odd job description, to be sure. And misunderstood — even by some of its practitioners. Critics, in the view of most people, exist for two reasons. One is to pass judgment. Rudely, if possible. The other is to function as a consumer guide, advising people what they should or shouldn't spend their money on. Hence the star ratings (introduced by the Michelin restaurant guides in 1926), the awarding of tomatoes, bullets, popcorn boxes, and those thumbs-up, thumbs-down pronouncements. It is as a consumer reporter that critics have — less so, in recent years — a niche in newspapers. And it is in this capacity that they are tolerated by their natural enemy, the artists. "I am essential to the theater — as ants are to a picnic, as the boll weevil to a cotton field," says Addison DeWitt, the quintessential snide critic, in the film "All About Eve."