A big problem has been those secret numbered bank accounts in some countries which allow corrupt politicians to raid government treasuries and take long vacations and early retirements in Switzerland or the Carribean. Too much foreign aid has been given to large projects that will turn a profit for the donating countries. Multinational corporations have relied on bribery and a supply of black market arms as the way business is done in Africa. All those dictatorships would never have happened if it wasn't profitable for 1st world business interests. When you get down to the nubs business doesn't like all the rules and regulations that democracies generate. Businesses are run like dictatorships and they prefer governments that operate like businesses.

It may be that the Westphalian nation-state template just doesn't fit for Africa. It does not necessarilly fit all that well anywhere, even in Europe (where it is in the process of being extensively modified), but it is especially ill-suited in Africa.