I have been to Africa a dozens times, staying the weeks and months at a time. I see Chinese people in Africa securing contracts building plants and taking over resources. Cacs have already been making billions upon billions off of Africa. I have relatives that live and work in various countries throughout Africa. Many African countries are still being exploited by outsiders. Africa has more natural resources than all the other continents put together. Why is Africa still poor, it is not by accident...it is by design.
Exponential growth takes time, dude. China is just now, in 2013, starting to develop a middle class. Africa's leaders have to make the right moves in each of their respective nations to make sure that the wealth that they will see from globalization and natural resources will help develop a middle class.
If the Chinese and other nations want to invest in infrastructure, let them because that is still a net gain but they have to be leery of how much control they let outside forces in... they do need investors and those nations have stepped up at this time