Ben Abercrombie was feted on a Thursday late last May, on the top floor of the tallest building in Cambridge, Massachusetts. Roughly 60 of us were gathered in an industrial event space on graduation day at Harvard , looking eight floors down from an outdoor deck at the students milling below in caps and gowns. The owner of the space, and its famed first-floor taqueria El Jefe, was greeting new arrivals and handing out drinks, acting as the evening’s major domo. For years, John Schall had been a