Actually, when you compare Haiti to the American South, the only thing they have in common is slavery. The situation in Haiti was much different - there wasn't exactly a Napoleon to deal with, for one thing. And the French emperor's heavy hand had a large thing to do with the thousands of dead French soldiers. (After seeing that, I'm not sure how any American general, Southern or Northern, could suggest African people couldn't fight...) In the end, the Haitians gained their independence and that was a fine accomplishment. But it also lead to chaos and poverty - they were exploited by all sorts of foreign countries and petty dictators. It was a direct result of the French Revolution. The leadership had military men - Gen Toussaint L'Ouverture, for instance, had served with the French military against Spain. Very different situation and circumstances and outcome.
Emancipation, and a little (very little!) help from the government, and a lot of elbow grease and help from each other - the American ex-slave came out of it remarkably well. They did more, too, than just sit on their watermelons waiting for the white man to free them. They fought for their freedom in non-violent but very effective ways - work slowdowns, for instance. They knew whose work fed the army fighting to keep them slaves.
They also knew that if they did a Nat Turner even their friends in the North would turn on them for violent savages. As mentioned before, the situation in Haiti was far different than the situation in the South. As it was, the Jim Crow and black laws were an effort to 'legally' re-enslave them and it worked fairly well - but there was another civil war that finally removed most of the shackles. This was not bloodless, either, but far less bloody than outright war.
Lincoln and Brown were likely both right on viewing the necessity of a national atonement. Individuals largely felt they had nothing to atone for - that they had even been most kind to their poor benighted charges. Where does that fit into your suggestion of justification for the kind of woe that befell Haiti? If an atonement is required of a nation, is it required of individuals as well? Guess that happened - most of the planters ceased to be the wealthiest and most powerful people in the country. Again, though - isn't a willingness to be chastised necessary for that? An acknowledgement that you did wrong? Not many slave owners thought that.