A lot of it really is just basic economic development. Africa needs all the foreign investment it can get. A stadium is better than no stadium, regardless of how little perceived benefit it is to the "average" Zimbabwean. Western NGOs have a tendency to forget this and end up throwing money on unproductive social projects that are even less beneficial to the "average" man than a stadium. China got significantly wealthier over the last decade from undiscriminately accepting foreign investment all over the world. The Chinese appear to have considerable faith in Adam Smith's "invisible hand," while many leftists in the West have lost that faith.
As French and Bolshevik revolutions demonstrated, scouring will scour, burning will burn, slashing will slash.
What is needed is building, humility and patience. Things like stadiums add to the infrastructure of civilization. Purging, killing, bombing will satisfy Puritan arrogant passions while bringing misery and destruction.
Mao killed somewhere in the neighborhood of 100 million Chinese during his rule. South Africa has a population of just 44 million. Genocide on that scale is well within Chinese capability