They have an incentive to uplift since their interest is in a cheaper goods/an export market, not profit. The profit motive doesn't care if goods are expensive only that profits are high, meaning that profit driven foreign relations would want Africa to stay underdeveloped since less developed industry equals a larger porportion of value that can be extracted from labor. If the industry is very well developed then you will bearily make a profit since you can't exploit machines. You don't see this in capitlaist nations in themselves because competition forces the development of Industry but this in general one of the contradictions of capitlaism.