1) We don't always know who is one of "the greats" of today's generation, until much later.
2) Today, content generation is so democratized (eg wikipedia, soundcloud) that there are less individual superstars like Pushkin, etc.
3) Even intellectuals who were once highly regarded would today have tons of comments on their blog nitpicking and debating every detail of what they said, with many of the comments being low quality. See eg Sam Harris vs Noam Chomsky debates.
It seems like a world in which it's harder to be great like Alan Turing or Claude Shannon or Richard Feynman or Marvin Minsky. At the same time, maybe there are more great people than ever, and we just don't always know who they are until much later.