I've visited Africa on a number of occasions, including North Africa, Southern Africa and West Africa. My family lived in Nigeria for about 5 years - and for some of that time I lived there occasionally.
In my opinion, most parts of sub-saharan Africa in general are god-awful shitholes, and I wouldn't send my worst enemy there.
Are there nice places in africa, where you can live relatively safely? Absolutely, just like there are incredibly dangerous places in the U.S. But ON AVERAGE, sub-saharan africa is a giant horrific mess, filled with corruption, superstition and savagery. In Sudan today, human slavery is widespread, and crucifixion is used to execute people!
Living in Lagos, the capital of Nigeria, were we safe? Absolutely. We had chauffeurs for all of our cars (so that hopefully the chauffeur would be the one dragged from the car and killed, not us, in case the car hit someone), we had a walled compound with razor wire and broken glass on it, we had steel doors to the upstairs and steel bars on the windows. Were we safe? Sure, to a point - but my father was warned by the home office in London not to investigate corruption at the company he managed, because the corrupt managers would just pay one of the cooks or guards to kill us.
Did I mention that a common cause for traffic jams was corpses in the road? Or that you were held up at gunpoint at military checkpoints, so that guys with assault rifles could "search" your car for money? Did I mention how a tank was parked in front of the house during one of the military coups - firing it's main gun into the house across the street (where a government official supposely lived - notice I said supposedly, because the idiots had the wrong address and shell the wrong house
).
Keep in mind, this is in the HIGHLY modern and sophisticated capital of Nigeria - an OPEC country. Not like the more primitve countries like the Congo, or Uganda or Rwanda. But the real danger in Africa is the instability and unpredicability. When my parents lived in Nigeria, Cote D'Ivore was a great place to go for a long weeked or a short vacation, because it was super-safe, civilized and stable. Ten years later, and it's the usual mess of civil war and violence, with French troops depserately trying to keep different factions from killing each other.
I completely agree that if we want to tally atrocities, Africa has a long way to go to compete with pros like Pol Pot, Stalin, Hitler, etc (although Africa traditionally has also not had the population densities, but that's a different matter). however, the underlying issue is that the West, and large parts of Asia are GENERALLY STABLE, and just ocasionally erupt into war and ocasionally get some demagogue in charge of a country who does horrible stuff (that's human nature - what are you going to do?) - but Africa is GENERALLY UNSTABLE, and seems to show little tendence to change that.
but - I have no idea what the CAUSE for Africa's problems is (there are many fascinating possible ocnversations to have, but the usual suspects would get them locked on ar15.com) - but in general, it IS a continent rife with danger, violence and superstition.