I don't think that African dictators are rejecting reason and evidence in the course of administrating their corruption, although they might reject evidence of corruption in public.
South Africa isn't a dictatorship, but the voters still vote along tribal lines, with a concerning minority (+-10%?) voting along race-hate lines.
Jacob Zuma came to power partially because he wasn't an AIDS denialist, and one of the few things Zuma can claim credit for was widespread availability of anti-AIDS drugs, and the resultant recovery in South Africa's life expectancy.
AIDS denialism is pretty-much dead in South Africa....it only ever was a pique of Thabo Mbeki, and because of his power as head of the ANC, the rest of the leadership had to be sycophantic.
Which means that as far as loss of human life goes, Thabo Mbeki belongs to the same category as Vladimir Putin with his war of conquest against Ukraine. Only the process wasn't as overtly violent, so the world didn't particularly care.
In my mind this mental framework features capitalism, democracy, and a style of thinking that emphasizes - or at least accommodates - kindness, openness, progress, thinking in nuances. Basically, humanism.
From my experience there, some population groups will reject ideas they see as white, which includes capitalism (origin: probably Europe?) but not communism (origin: Germany!). Others, including white folks, might feel inclined to embrace those "white" ideas specifically, but will reject other parts of the Enlightenment framework. Many think problems should be solved by force instead of careful and nuanced consideration, which is seen as effeminate.
Corruption is more of a symptom than a cause.