While it is of course a stupid thing to believe and even more stupid to say out loud it is not some bit of nonsense original to him but rather a long-standing "theological urban legend" in certain quarters (
here's a page from 2004 and there was an upsurge in such rumblings back in the early '90s when Bush/Clinton were dealing with the first Aristide ouster; we just didn't have YouTube).
I'm not at all surprised to learn that Robertson travels in those quarters.
What is surprising is people who think this is a good riposte (as I've now seen in several places: "So what he's saying is god has spent 200 years punishing people who simply live near where other people did a bad thing. Who would believe in such a god or hold to such a moral system?" I've been seeing that from Christians. Is not such an idea, in essence, the fundamental belief of Christianity (and plenty of other religions)? If original sin isn't crazy then god punishing Haitians because of misdeeds isn't particularly crazy either.