Why is so little known about the indus river valley civilization

Much of what is ‘known’ about the Indus Valley Civilization is false. For instance, we are told that the writing may never be deciphered. The truth is that it was deciphered in 2010 and the results may be seen at the Indus Script Dictionary on Facebook. Claims have been made that Indus people spoke a Dravidian language, but most of the deciphered seals and inscriptions yield Prakrit or Sanskrit names and words. Claims have been made that horses did not exist in India during IVC times, yet the biologist Sandor Bokonyi identified the bones of true horses from a number of IVC sites. I’ve even seen textbooks that claimed that IVC people were peaceful, did not use money, and knew nothing of the Hindu religion. Yet many of the seals contain names ending in ‘-biren,’ which means ‘lord of warriors,’ and gold and silver sequins were found in an IVC treasure trove in Mandi village, and several seals encode the names of Hindu deities, including Agni, Kali, Shiva, Andajan (Brahma), and Ja (Vishnu).