The idea that someone from Haiti could get to Nassau for a visa interview is not serious.

There's no staff in Haiti to process visas at all, the embassy is on ordered depature. There are staff in Nassau, including people trained in Haitian Creole, and there are many Haitian applicants who apply for visas in Nassau. Where do you think the US should interview Haitian applicants? Also, if someone from Haiti has the resources to travel to the US, they have the resources to travel to Nassau for a visa interview.

The Darién Gap was believed to be impassable, now people cross it by the thousands just to get to the US. You're seriously underestimating how motivated and desperate some of these people are.