That's it right there. The worst of them left after the collapse of their white supremacist paradise. Every time you see a South African immigrant in New Zealand (for example), chances are they're racist shitbags.
I despise Apartheid though perhaps we should point the finger less at our predecessors and act on similar oppression today.
When there is significant evil in our societies, is it enough to say I didn't support it? Or are we obligated to put a stop to it? The latter is a harsh, demanding judgment, but that doesn't mean it's not true.
Tacit opposition is no different than tacit support.