Well, my one datapoint on this whole matter is that the overwhelming majority of scams on my sites come from that region of the world, so I'm about ready to write off the whole continent in terms of doing business. If I were to write a bayesian scam filter, "Comes from Africa" would be one of the most important positive signals.

I would assume that many other businesses have shared this experience and come to the same conclusion. Things are getting better, I'm sure, but they're not near the "worth my time" threshold yet.