All of them had one thing in common. They had pride. They appointed themselves as gods over their people and demanded their worship. Because of their power, millions under them were forced into idolatry and human worship. And I am not even discussing the cruelties of these Kings for eg. Pharaoh ordered the execution of all male offspring of the Hebrews. ( I still shiver with fear thinking about that)
I am quoting Hazrat Jaffar, the cousin of Prophet Muhammad, when he went to the Abyssinian King to demand asylum:
" O king! we lived in ignorance , idolatry and unchastity; the strong oppressed the weak; we spoke untruth; we violated the duties of hospitality. Then a prophet (SAW) arose, one whom we knew from our youth, with whose descent , conduct and good faith we were all acquainted. He told us to worship One True God, to speak the truth, to keep good faith, to assist our relatives, to fulfill the duties of hospitality and to abstain from all impure, ungodly and unrighteous things. And he ordered us to say prayers, give charity and fast. We believe in him, we follow him; but our countrymen persecute us, torture us and tried to cause us to forsake our religion."
This above encapsulates pretty much everything that is needed to prove that these strongmen were wicked people.
Excellent point