According to veteran Toronto art critic John Bentley Mays:
Art criticism is a form of city-building, quite as much as urban design, architecture or community activism. It is a contribution to urban intelligence, a strengthening of the public space in which citizens meet and recognize each other as parts of the civic whole. In the absence of a clear commitment to urban civilization on the part of the writer, criticism deteriorates into the nattering of coteries, trivial point-scoring and bookish monologue.
Read more of his thoughts here.