Why are masterpieces no longer created?

How come people don't write as well as Shakespeare or Tolstoy did? Or is it that they're just not revered as much? How come music no longer compares to that of Beethoven and Mozart? Even in films, films from just thirty years ago, like The Godfather or Lawrence of Arabia before that seem vastly more complete and perfect pictures than anything that comes out today - even directors like Scorsese and Spielberg who created some of these works can't create as good pieces nowadays. Why does modern culture no longer seem to create as good pieces of art as it used to?