Probably GD is the best place for this.
First let me state my position, I totally disapprove of apartheid and I judge people (harshly) by what is in their head - ‘culture’ as I think MrDibble said earlier. I also dislike what has happened in Africa and feel sorry for all involved.
As I see it, the major problem is that Africa has porous borders, the only real barrier is the Sahara. Consequently troubles in Darfour spread over into Chad, troubles in Somalia spread over into Kenya, disaffected Zimbabweans are turning up in South Africa.
Where you get migration of large numbers of people, you get poverty, slums, violence and criminality. You get a sense of impermanence, so any sensible person tries to grab as much for themselves - in effect corruption becomes rational.
There is also a strong tendency for people to migrate from the country where they have a subsistence level existence, to towns where they think that they will be better off.
Probably the only thing that holds people together is ‘tribalism’, but the downside of that is that leaders tend to be selected for who they know rather than ability. It seems that in South Africa there is a demand for ‘token directors’ of companies, who get paid rather well - but only contribute their contacts. It was interesting listening to one of them on BBC’s World Service (the UK version is the one they broadcast to Africa).
I reckon that the two conditions for an affluent society are stability and education.
Both are difficult to accomplish with infinite migration.
Interestingly Mugabe ran into the migration problem, his slum clearance was harsh, but it was easy to see why he did it.
As I see it, South Africa needs to eliminate inward and internal migration and concentrate on giving its own population a vested interest in stability. I’m not sure that is possible.