Yeah unfortunately stuff like this happens all the time, but you're generally ok in the populated areas unless you go looking for it. I was born there, lived there (in Port Elizabeth) until I was 17, and then we moved to the UK. My mom is British, dad South African, and I really do miss SA but I wouldn't live there now. I've had far greater opportunities here in the UK since moving here, and the only thing I still can't get used to is the terrible weather we get here all year around. There's just no consistency.
Still, I'd take that over being mugged / hijacked / shot any day of the week.
Before we moved here, my dad was mugged and after he handed everything over the guy ran off and dropped some razor blades. To this day it still really worries me at what might have happened.
I have friends that live in Sandton in Jo'burg, lovely area, but they have patrol guards that operate little checkpoints in the suburb streets. They are armed and do head counts when people leave in their car and then compare when they come back in. I'm not sure if this happens anymore, it has been about 14 years since I was last in Sandton. They have an electric fence around the top of their high garden wall, and a huge iron security gate within the house that is locked at night, this locks off the part of the house that they sleep in. They have woken up numerous times to people burgling the rest of their house whilst they're in their rooms. One night they went out to the gate, and the men in the house had machetes and knives. Obviously they were safe behind the gate but again, it makes you wonder just what could happen.
If you want to protect your home these days, then the only way is with armed response, which most houses have. Private security firms must be making a fortune, although it must be quite an unsafe job to do if you're a patrol man, even if you're armed.
Sure, you can say that a lot of places are unsafe, but you shouldn't have to go to such lengths to protect your own home.
My parents still go back for holidays, although I do worry about them when they go. It really is a beautiful country but these days it is just so unsafe.