When the Museum of Modern Art wrapped up six months of foregone agonizing and decided to raze the American Folk Art Museum, it claimed to be sacrificing a small work of architecture for the sake of Big Art. MoMA’s prescription for the ideal viewing experience is more galleries, more wall space, more hallways, and bigger lobbies. MoMA isn’t so much growing as it is engineering itself to pump high-volume crowds as efficiently as possible through its art-lined pipes.