This is kind of ignoring the elephant in the room, which is that Haiti was born from a successful slave revolt and and one of the first things it did as an independent country was to expel or kill virtually all the whites, expropriate their property and destroy all the institutions associated with them. Both culturally and genetically (95.5% per Wikipedia), Haiti thus has a lot in common with sub-Saharan Africa, anot…
Thirteen years of conflict and war took place before this happened. Why? Enslaved people wanted what the French Declaration of the Rights of Man guaranteed, that "all men free and equal."
In struggling for this Haitians were bounced around like a football, between the great powers of France, Spain, and Britain.
Every attempt at autonomy or freedom was met with outright force or duplicity aimed at returning Haiti to the status quo of one of the most brutal forms of slavery in history.
What's the saying? Fool me once...
Dessalines, who ordered the 1804 massacre, had seen all of this, topped off by the French just a few years before taking out Toussaint Louverture, who was forgiving of whites.
He had also seen brutality the likes of which we cannot imagine
the French staged mass executions via firing squads, hanging, and drowning Haitians in bags
Rochambeau invented a new means of mass execution, which he called "fumigational-sulphurous baths": killing hundreds of Haitians in the holds of ships by burning sulphur to make sulphur dioxide to gas them.
Should you still think the Haitians more brutal than others, do read up on the British and French exploits in continental Europe during the Peninsular Wars. God help you should you find yourself a non-combatant in a place just taken by siege.
Haiti was born in brutal slavery. It has been meddled with incessantly throughout its history by greater powers. If we want to trace a line back, those are the dots to look at connecting.