The problem of South Africa is more ingrained than we can see; firstly, the level of illiteracy among the blacks is higher than that of the whites. Hence the reason for the bitterness that foreigners are taking their jobs. And it makes it easier for some local ruler to rile up their xenophobic tendencies. Anywhere in the world, you won't see educated people behaving like animals, would you? Very rare!
Secondly, the apartheid government didn't offer education to the blacks or they are too laid back to make effort themselves too. Even when the Nigerian government offered scholarships to South Africans during the apartheid regime, the prominent memory I had of South African students at my university then was that of lazy drunks. So you can understand Botha's sentiment towards them. As hash as his statements maybe, there is some elements of truth there. But what he fail to understand is that you cannot lump all blacks together. Even the educated black South Africans cannot be lumped together with the illiterate ones.
We are all aware that the whites think they are superior to all other race, but that is far from the truth. It's all ego, and nothing else. No race is more superior than the other. It's sad that the misfits who are perpetuating those animalistic acts give fuel to opinions from other races about blacks.