The South African government impoverished many whites and they cannot afford to get out.
First of all, you need a visa to get out and a place to go. Good luck with THAT; both are extremely difficult to get.
Secondly, there is a law in RSA, re the amount of one's own money that is allowed to be taken out of the country and it's not a large amount.
And lastly, the ANC has impoverished many non-ANC members and ANC family members and friends, regardless off race.