Like someone else said one main reason is Haitians are the most woke and most proud to be Black and not afraid to show it. I'm sure its not 100% percent perfect just like other nationalities and there are exceptions, but Haitians stick together alot more and its not even close. Other caribbeans like Jamaicans are the polar opposite, and have more in-fighting and are not as "woke".
Ironically whether other Caribbeans or AAs, i feel people started to view Haitians(wrongly i might add) for being too "bougie" or "stuck up" simply because they stuck together alot and spread lies about them and made fun of them and started this nonsense about them smelling or being dusty and ugly. Many times its just straight up jealousy.
AA groups have toned it down over the past years and aren't as bad like in the past, but other Caribbean groups still view Haitians in a certain light.