My understanding from old timers in Belize is that Kriol originally came out of a variety of cultures attempting to understand and speak the English they heard.
Different cultures and people from different countries who were brought to Belize has no common method of communicating with each other except obviously via sign language. There were so many different tribal African and Indian languages being used that a simple language evolved which had a common understanding.
In times past when travel was very limited often different languages evolved within different villages within close proximity to each other.
Kriol simply was the only solution. It is clipped and very non descriptive. The mind fills in the gaps.
I understand it well. SIN speaks it fluently. Perhaps he has another comment to add.