Which explains why there is so little information about the Indus Valley civilization?

The Indus Valley Civilization remains one of the most enigmatic events in human history, if only for the paucity of knowledge associated with it in general discourse. It was truly a paean to the desire for human excellence, even in those times, bringing in its wake several important inventions which mankind has derived progress from. Each and every one of the 4 ancient civilizations had its own mind boggling languages, handicrafts, religion et al. Here I am only concentrating on the amazing and unique things found exclusively in Indus Valley Civilization.