Well, because such a conversation would be meaningless and irrelevant - why would you want to talk about something that never happened, rather than trying to heal the rather nasty wounds and divisions created by Apartheid, something that DID happen and the effects of which are still heavily weighing on our society?
Or would you rather be talking about a hypothetical ANC/SACP regime back in 1960 rather than the real and tangible effect of Apartheid because - like most white people - you'd rather not face up to your complicity in that crime?