I don't like dreads on anyone as a part of a fashion, but this is just touristy shit, and the tourist industry feeds people.
That hair style is a part of their culture. Why make fun of it?
The matter is not about whether it looks funny or not, it doesn't belong to the place where it's worn. Go to a hair salon and get it while you are on the island and then go back home to the West where dreads are fine.
Black people should be comfortable wearing whatever hair style they like. It isn't on you to deem it inappropriate.