On this forum I learned that disliking the ANC's track record in governing South Africa is "dog whistling". So I tend to agree with the OP...
Who said that? Most lefties here are huge opponents of Mbeki's and Zuma's legacies, we just think:
a) the opposition is worse
b) a large section have of the international media have a huge hateboner for the ANC, and melodramatically proclaim problems common to all developing nations (crime, corruption, inequality) as proof that SA is DOOOOMED
c) by and large white South Africans are the whiniest people on earth, given that the ANC essentially saved their bacon from some kind of Malema/Mugabe style figure at best, and an ethnic civil war/genocide at worst
d) the mockery of poor, black South Africans for continuing to vote ANC (as proof they are "uneducated", sometimes with the even more insulting insinuation that they are "too uneducated for democracy) is highly distasteful. And almost certainly a dogwhistle - nobody says, say, Italians' problems with corruption means the peninsula had democracy prematurely.