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.
I'm sure it's much easier for these corrupt thugs to sell out the assets of their countries to the chicom, who could not care less about anyone's rights. Think of the people of darfur.