Robin Hemley ponders their persistence:
Curses most often belong to the dispossessed, their last and ultimate defense. The best curses come from those who have a history of oppression. Think of the Roma in Europe, Haitians, Afro-Cubans, "Can curses pierce the clouds and enter heaven?" Queen Margaret asks in Richard the Third. A curse is a last resort, when earthly justice fails, an act of desperate rage that requires no surefire answer from God as to its efficacy. The curser curses first and takes credit later.
One of Hemley's favorites comes from the Algiers section of New Orleans, recorded by Zora Neale Hurston:
"That the South wind shall scorch their bodies and make them wither and shall not be tempered to them," it reads in part. "That the North wind shall freeze their blood and numb their muscles and that it shall not be tempered to them. That the West wind shall blow away their life’s breath and will not leave their hair grow, and that their finger nails shall fall off and their bones shall crumble. That the East wind shall make their minds grow dark, their sight shall fail and their seed dry up so that they shall not multiply." This is only a fraction of the text of the curse, which ends despairingly, "O Man God, I ask you for all these things because they have dragged me in the dust and destroyed my good name; broken my heart and caused me to curse the day I was born. So be it."