Tom's answer is correct. The USGA thought Pebble Beach was too far from a metro area to draw a crowd that would make the Open a moneymaker. Then and now, the Open was the USGA's cash cow. By the late 1960s, with golf growing (and crowds for the Crosby Clambake growing), they took a gamble and awarded Pebble the 1972 Open. The crowds were good, Nicklaus hit that 1-iron, and the rest is history.