It's much more complicated than that. One of the legacies of apartheid which was violently opressive is a violent - often gratuitously so - society. One of its successes was keeping different cultures and races apart and creating chasms of fear based on differences rather than our common humanity. The recent rise of nationalism and populism - not just here - undermines the good that had been achieved and foments division. Having walked the path into democracy, it's tragic.

This is coupled with (often) white paranoia. My observations. The advocates of the death penalty are often in the latter group and see it as vengeance rather than punishment. IMO it's all a lot more nuanced than you suggest.