South African men seem to have developed a really scary culture of violent dominance over the last 20 years or so, and gang violence is pretty-much endemic here. Not to say that everybody is in a gang, but that same kind of dog-eat-dog mentality is widespread, where you constantly have to prove yourself through violence. It's male dominance taken to an extreme, and obviously the thought of a woman not "wanting" a guy "as a man" is a huge threat to his ego, which is what that entire dominance is based on. Likewise, "men dressed like women" undermine that idea of dominance, and they have to be destroyed.
It's not unique though. It's expressed over here with particular brutally, but the ideas behind it seem universal - when I first came out to a gay friend of mine in London, he just couldn't fathom why I would want to give up being "a man" (said with such reverence it made me feel distinctly uncomfortable) to be a woman, which, in his words, "Are in every way weaker and less able. Not their fault, just nature." We've since drifted apart, as you'd imagine.
I doubt that I'm going out on a limb when I say that that attitude is probably very nearly universal among men, even if they never say or show it - even if it just manifests in the need to "protect and provide", and it's the same root cause of violence against women, trans people, gay people and probably a host of other bad things.
Mina.