Comparing all of Africa is even more bizzare then comparing all of the USA. Imagine if somebody in South Africa said they were afraid to go to the parks in Montana like Glacier Park because they had riots in Detroit.
There are 60 countries in Africa it's not a single government for the whole continent. South Africa is a very safe and comfortable place to visit. There is no more threat to your safety then anyplace in the USA when with a safari company or on a park tour. Sure bad things can happen but the odds are no more then what could happen to you in your own neighborhood.
There are some bad places in Africa. Zimbabwe and Uganda for instance. My policy is that I will not arrange a hunt for anyone in a location I would not take my wife and family. South Africa is as nice as anyplace I have ever been. Kenya used in the example above is not even open to hunting so who cares what their situation is for the hunter. It's also thousands of miles from South Africa.
Namiba, zambia, Botswana, and South Africa are as nice and safe as anyplace your likely to visit on this earth. I would certainly have more worry over visiting New York City, Chicago, or LA. Don't lump all the countries on the African continenet together any more then every location in North America.