Apparently because it's got it's own identifiable syntax (whatever that means) patois qualifies as a separate language, rather than being a form of English (even though a lot is carried over from English and other languages in Jamaican history).
Always makes me laugh when some wannabe 'rude-bwoy' who was obviously born and bred in UK tries to speak it like he's from da Yard - rhaaaatid !!
You've gotta read the whole lot for the full effect, anyone been in Belize and listened/read any kriol/creole ?
"His friends had hat,s he didn't. He's a barber, he put one mirror in front of him and one behind to cut the hair like he did.
He won a contest with the style and got a box of Guinness for him and his friends.
On his way home from a party, a policeman shone a torch on the hairstyle and couldn't believe it, and when he went to the station to show him in daylight, the policeman shook his hand and told him that he had a talent."
Its not that hard but think that's enough. More than enough.