Except Africa is, by the majority, not Christian. You can't blame the pope on this one.
And anyway, the deal is in Africa, like karajorma said: you need lots of kids, because lots of kids die. it's also still a mostly agrarian society, so in order to grow food, you need workers, and what's a better labor pool than your own children? The only problem is that they're not producing enough food to feed their kids, so once they die, they still need people to work the farm, therefore, they have more children.
While an0n's view may be more "morally uplifting" in the sense that you're transferring the blame from everyone who should be helping them, to the people themselves, thus saying that they can all go to hell because it's their fault and as thus they deserve it, it's not the right view.