“The Metrpolitan Museum has long been the jewel in the crown of the Upper East Side, a sprawling wedding cake of a building celebrating the marriage of art and money. In the past few years, however, some of the museum’s neighbors have begun to see the Metropolitan less as a refined repository of priceless cultural artifacts than as a tacky tourist attraction of idling school- and sightseeing buses, souvenir sellers, and street performers—far more democratic than Fifth Avenue has ever considered desirable. Then, in 2000, the Met threw down the gauntlet, pushing a plan through the Parks Department that called for a 200,000-square-foot expansion” and the neighbors revolted…