A Bad Rep
When Jezebel was Queen of Israel, sweeping changes in Israel's religious and political power base swirled through the land. For thousands of years the people of that region had observed a religious tradition that involved numerous gods and goddesses. Jezebel's parents were the high priestess and priest of Ashtoreth and Baal in her home in the Canaanite city of Sidon. They represented the goddess and god of an ancient pagan system. In this ancient religion, knowledge, power and property passed down through the mother. It was a matrilineal system in which women had social, political, legal and economic independence. Into this environment came a group of Hebrews, Levites, who taught a new way of thinking. The Hebrews insisted there was but one god, a male god. Convincing people to change their core beliefs wasn't any easier then than it is now, and the Hebrews faced strong resistance from the followers of paganism.
Jezebel and her husband, King Ahab, refused to accept the new god. They clung to the old traditions and openly fought against the acceptance of the new monotheism of the Hebrews.
The battle for religious dominance became an all-out political war. The book of Judges in the Old Testament is little more than a recitation of all the massacres and murders carried out against the infidels who worshipped asherah and baal "on every high hill and under every green tree." In 842 B.C. Jezebel and other members of her "cult" were massacred by order of the prophet Elisha.
We know how this war ended. The believers in the "one true God" won.
Her sin was that of disagreeing with the ultimate victors in the battle of faith. To quote the movie Lone Star, "The winners get the bragging rights." The winners used those rights to make Pagan a bad word, and Jezebel's name an insult to be used to shame women whose behavior was beyond the control of men.