Well... there were a lot of things said by the Israelites about those they termed the "Fallen Ones" ("Fallen Angels")... all bad, of course. And all in error.
The historical fact is that the period of time in which these "Angels" appeared pre-dated the existence of the Hebrews/Israelites by literally thousands of years (they descended to Earth ca. 10-8,000 BCE while the Hebrew/Israelite nation was not established until at least 6,500 years later). Those the Hebrews chose to call the "Nefilim" ("Fallen Ones") were, in fact, the "Anunna" gods (erroneously called "Anunnaki" in modern times) by the Sumerians who lived in Mesopotamia where Abraham was much later born and raised. Thus, Abraham took with him to Canaan the history and culture and mythology of his Babylonian ancestors... including the ancient accounts, even in his time) of a small group of celestial visitors who descended from the skies, lived amongst Humankind and taught them pretty much all they knew.
These Anunna were venerated as gods, and their children as demigods, by the Sumerians to whom they originally appeared... because of their benevolent nature and what wonderful benefactors they were to Humankind. The ancient Egyptians were likewise visited by either this same group or a similar group of "angels" whom they called the "Shemsu Hor" (Sons or Family of Horus). Like their Sumerian counterparts, they likewise taught civilization to the ancient Egyptians and were equally revered.
These are exactly the accounts Genesis 6:1-4 references when speaking of the Nefilim children as "...mighty men as of old, men of renown."
The point being... when they were actually here and for thousands of years thereafter, they were regarded as heroes, as demigods, as wonderful benefactors. Only in a distant land almost a thousand miles away and thousands of years later were they written about in a negative light. And unfortunately, as the Bible/Torah has come to be just about the only ancient text to be commonly known and read in modern times, only this erroneous negative light has survived, as well.
The "Fallen Angels" were not fallen nor were they evil. They were, instead, victims of a deliberate campaign of demonization by a far-later culture who never even knew them.
