For a creole to form, as people have noted above, it has to be children’s first language. As a pidgin, it does not have full expressive power; since pidgins are used mostly for commercial purposes, a lot of stuff like how to say you love someone or how to talk about what you did last summer is not a part of it. But, when a pidgin is used by children as a language, it needs that full capacity. The beauty of language and acquisition is that children can do this.
There’s a theory that’s name I can’t remember, but it states for a pidgin or creole to form, you need at least two substrate languages. Substrate languages, which in the case of most Caribbean and African creoles I know are African languages, form the grammar of the creole. The superstrate languages form the lexicon and are the target languages (i.e., the more prestigious language), and these are usually the European languages. Anyway, if there are two different groups who are trying to communicate with each other and with the colonizers, this forms the perfect environment for a creole. For instance, in the Caribbean, people from so many different linguistic groups from Africa are brought together as slaves. In order to do what you gotta do (do your work so you can get food, talk with other people so you don’t go crazy, etc.), a common ground has to be found, and that common ground is the pidgin. When people get together and have a kid, but have no common language besides the pidgin, the kid learns the pidgin, and voila, a creole is born.
So, yeah, this was kind of rambly, but I think one possible reason some places didn’t from pidgins or creoles was because there weren’t two substrate languages. In Africa, from my understanding, it is common for people from different groups to have a lingua franca, so while they may be from two different linguistic groups, they can communicate, so the pidgin is not needed between the people whose languages would have formed the substratum. Their children are not going to hear pidgin growing up as a first language, and what pidgins their might have been at first to deal with colonizers died out because of widespread adoption of the colonizers’ languages or something else.
Also of interest might be the creole continuum.
Did that make sense? I’m not a creolist, but I’ve studied them a little. I don’t want the above to be thought of as the be-all, end-all answer; more like an informed opinion. If you’re really curious and want to know about Africa in particular, I would suggest looking up the work of John Singler or even emailing him. Renee Blake, John Rickford, Salikoko Mufwene, and Don Winford have done a lot of work on Caribbean creoles and creoles in general.
