That's an interesting question, but I fear this fact is more telling about our era. In other times any great person would have read and read again Plato, Aristo

That's an interesting question, but I fear this fact is more telling about our era. In other times any great person would have read and read again Plato, Aristotle and the like. I don't think it is very likely that those classics which have been considered useful for so many people during such a long period are magically not useful anymore. Maybe it's just because what we consider important people are not that important. Side note, Paul Graham is likely to be more interested in philosophy and "real books" than in those ego building books you find in airports.