The surplus of resources, I guess. The disposable income of a nation.
It doesn't make sense, it's just someone painting the Haitians as a short-sighted and reckless people (which I believe is untrue) without giving any reasons why they believe this.
The entire reason they were a colony was due to having vast amounts of arable land where coffee and sugar cane was grown. That's ignoring the natural beauty of the country that would be ripe for tourism if they had corruption and crime under control.
It doesn't make sense to act as if Haiti is a barren wasteland with no possible way to generate wealth. The "marshmallow" is quite literally the wealth the country as a whole can generate. They are one of the worst countries in the entire world when it comes to corruption index:
Who did that?
Here's the first result that comes up when I do a web search for "how corruption works", it's pretty informative for those who are unfamiliar with the concept: https://www.transparency.org/en/what-is-corruption