Akhenaten was the world's first true iconoclast, or "image breaker." In forsaking the worship of many gods for the worship of just one god, in a spiritual sense, Akhenaten put "all of his eggs in one basket," and completely disrupted ancient Egyptian daily life and belief systems.
He also failed his people as Pharaoh. How? Because one of the most important functions the Pharaoh performed was the religious ceremonies in the temples which in turn kept the Cosmos functioning as it should: i.e., the sun rising and setting every day, the Nile flooding to the right height at the right time, no plagues or civil unrest. The ancient Egyptians called this concept of everything going as it should, "Ma'at," a term meaning, "Divine Right Order." Pharaoh was the intermediary between the ancient Egyptians and their many gods -- he kept things going.
When Amonhotep IV became Akhenaten, he did more than just become the first pharaoh to change his name. A person's name was very important in ancient Egypt, just as it is today, but even more so, because the ancient Egyptians believed in the magical power of their name. "Amonhotep" means "Amon is satisfied," while "Akhenaten" meant "Of service to the Aten."
Besides changing his personal name (his coronation name remained the same), Akhenaten turned himself over to the worship of the sun disk, the Aten, and turned his back on Amon and the many other gods. He abandoned the gods his countrymen had worshipped and trusted for millennia to keep their lives safe and orderly. He closed the temples, which put hundreds if not thousands of priests out of work. He even had the name Amon chiseled out of public monuments. Then he moved the capital of Thebes to a barren location many miles north, to a place called Akhetaten, "The horizon of the Aten." In doing all that, he disrupted Ma'at in a big way. That's the why of his making so many enemies.
It also seems that in his later reign, Akhenaten also turned his back on far flung Egyptian territories in Palestine and to the South, eventually losing them, which lost Egypt prestige and revenue as well. This would have also angered the priesthood and the nobles who were opposed to Atenism.
I do not think it is any coincidence that the Hebrews were in Egypt while Akhenaten, the world's first recorded monotheist, was Pharaoh, and years later came out of Egypt as monotheists themselves. There are many parallels between Akhenaten's famous "Hymn to the Aten," which praises all creation, and the later Psalm 150 of the Hebrew Bible.
Many years after Akhenaten's death, the Pharaoh Horemheb erased all traces that he could find of Akhenaten, Nefertiti, Smenkhkare, Tutankhamon, and Aye from historical records. The city of Akhetaten was abandoned and fell into ruins and forgotten. Ironically, this also helped protect the modest tomb of a boy king who would come to represent ancient Egypt: Neb-Kheperu-Re Tutankhamon ... the famous King Tut.