The critical issue for almost all African countries isn't the corruption, tribalism, religious conflict, etc. Those are all maladies common to every nation on Earth, "developed" or not. You can't tell me the Germans, Poles, Czechs, Dutch, Belgians, English, French, Russians, Ukrainians and Hungarians having centuries-old beef with one another, switching allegiances whenever convenient and pillaging one another for resources and women isn't some "petty tribalism", and these guys went at it with the most lethal non-nuclear weaponry known to man, firebombing entire cities and exterminating whole religious groups while sending literally tens of millions of men to certain death on the battlefield. Postcolonial violence in Africa doesn't even approach 1/10th of the level of barbarity and loss of human life we saw in WWI and WWII.
The problem endemic to almost every African country (and this applies to the Middle East as well) is a devastating clash of traditional, smaller-scale cultures and social arrangements with the overwhelming scale and scope of modernity. Prior to the "scramble for Africa" and the slave trade, Africans across the continent had developed hundreds if not thousands of cultures, traditions, social mores, and practices that allowed for more or less sustainable, relatively benign government at a smaller, local scale. However, these arrangements do not scale up to the size of modern nation-states - it is far easier to keep an eye on and check corruption when it happens at the 1000 or even 10000 subject scale, but when you're talking about pilfering a national government responsible for tens of millions of people, it becomes an impossible problem to solve. At every turn, in an attempt to maintain some semblance of peace or stability, African national governments are forced into making short-term decisions (paying off a particularly belligerent tribal group, running roughshod on traditional peoples in an area chock full of easily exploitable natural resources, etc.) that all but guarantee long-term dysfunction and stagnation.
Europe and the US had the benefit of being able to co-evolve with the onset of modernity - it wasn't *thrust* upon them in one fell swoop, but occurred over 10+ generations that allowed for the culture to change and shift in ways that would accommodate the new technologies. And it isn't like it was a cakewalk for the West - the Industrial Revolution was almost purely an exercise in human degradation and misery, and modernity has led to a pretty ugly disintegration of family life. And don't forget those two world wars either!
I think one area where we can viscerally experience this clash of traditional and modern society is the unprecedented population growth that the continent has seen post WWII. On the one hand, modernity brought amazing advancements in medicine and nutritional science to even the poorest people in Africa - pills for sleeping sickness, pills/DDT spraying for malaria, knowledge of germ theory and wound management...the list goes on. But on the other hand, in a traditional society where a mother could expect to lose the majority of her children before the age of 5, getting pregnant early and often was the only way to ensure that her family would have enough people to work the farm, protect the livestock, provide for her in old age, etc. So post-WWII, we shock the continent with all these medical advances without any real change to the underlying culture (how would it change, it never had the chance to!), and end up with an incredibly politically/economically destabilizing population boom. And of course the West, having had the chance to adapt to the onset of modernity and co-evolve with it, significantly dropped birthrates without even much prodding from their own national governments - it just became *normal* for people to have smaller families.
I've written enough for now. Interested to hear your thoughts. I don't write this as a cop-out for all the various terrible dictators that have ruled and ugly ethnic feuds that have been stoked over the years, but instead to simply try and understand the true roots of the current dysfunction.