The word "failed states" is commonly used of five states, two of which are not found in Africa: Somalia, Liberia, Zimbabwe, the Palestinian Authority, and Afghanistan. Your application of it to the other forty-plus states of black Africa is unsuitable and irrelevant, and shows little familiarity with the real issues in Africa. If you visited Nigeria or South Africa, you would not feel that you were in a "Quarter-civilized African joke nation" - unless prejudice got in the way.