Why did Egypt try to erase the pharaoh who made the sun its only god?

Akhenaten tried to make the sun disc, the Aten, the only god of Egypt, and the Egyptians who came after him tried to erase him from history. For centuries Egypt's religion had been polytheistic, with hundreds of deities, each with temples and priests. Managing the temples where offerings were made was one of the pharaoh's core duties, and big temples were major landholders with vast estates. Crowned around 1353 BC as Amenhotep IV, in the fifth year of his reign he changed his name to Akhenaten, "effective spirit of the Aten", and founded a new capital, Akhet-aten, now called Amarna.

In his ninth year he went further. He declared the Aten not merely the supreme god but the only god, with himself as the Aten's son and only intermediary, and ordered the defacing of Amun's temples across Egypt. Images of the god were banned apart from a sun disc whose rays end in little hands. The reforms also cut away the economic base of the priests, because they abolished the cults of the other deities and the lucrative industry of sacrifices and tributes the priests controlled, while strengthening the role of the pharaoh.

It lasted only about 20 years. After his death, later pharaohs toppled the movement, and large-scale efforts removed his name and his temples from the records. Tutankhaten, the next king and probably his son, changed his name to Tutankhamun and issued a decree denouncing the decay of the traditional temples. Later king-lists skipped every ruler between Amenhotep III and Horemheb, and later texts called his reign "the rebellion". The pharaoh who tried to erase the gods was, in turn, erased.