This is for a few reasons. Firstly, Africans don't view themselves as Africans (most of them don't). They view themselves as from x tribe or y country. Because of this, much hostility is shared between groups, and so cooperating to harvest these things wouldn't be the easiest. Secondly, the Scramble for Africa basically ruined most chances Africa had of becoming a power, because the European nations came in & exploited most of the continent. Hope this helps!
