Is geography destiny? One strand of development economics, represented most vigorously by Jeffrey Sachs, believes so. Landlocked, mountainous states, like, say, Bolivia, face much larger obstacles in achieving economic growth than do countries with easy access to seaports, and navigable rivers. Sachs particularly likes to apply this theory to his current passion, Africa...Okay, so first the slave trade robs coastal (and later, more interior) African societies of their young adult males, a process that goes on for centuries. This leaves them often leaderless and divided, prone to further exploitation by Arab and European slavers.
...The second point is that the regions in which Africans tended to escape the depredations of slavery tended to be characterized by a greater degree of "ruggedness." It was easier to hide from the slavers in the hills. The authors do a ton of number-crunching to prove that over the centuries, Africans fleeing from the slave trade tended to congregate in more rugged regions.
Then, in an attempt to escape the voracious maw of the slave trade, the permanent patterns of settlement are abandoned and Africans increasingly move away from the areas that are best for growing economies (plains, river valleys) and move to more secure -- but harder to develop -- hills and mountain country. So African societies are first stripped of some of their most productive members, then chased on to the worst land. Sound familiar?
Finally, with the end of the slave trade the Europeans just occupy Africa outright and impose highly unequal economies where a tiny minority of whites concentrate the wealth of whole nations in their hands -- a process that only petered out in the 1980s, by the way. (Zimbabwe, for good or ill, was only allowed majority rule a year before my birth.)
But no, I'm sure the responsibility for Africa's problems lies only and exclusively with Africans themselves.