As i understand, China's "non-intervenist" policy is based on its history of being weak and diasterous resilts when it does intervene. intervening might draw themselves into direct conflict with vastly more powerful countries. the fear is another 100 years of subjectgation by foreigh powers. China was poor, isolated and fearful. Their enemies on all sides--remember even the USSR become an enemy. Better to stay out of trouble. But if its core interest is under attack (Vietnam, North Korea, etc), then it will intervene for the survival of the regime. In Syria, China stayed silent...because It is not China's core interest. When it did interven during the Sino-Viet war, it was a disaster. China could not project power hardly. So being smart leaders, China official policy remains non-intervention.
As China become stronger, it will be less non-intervenist...because it is better at projecting power and is less afraid. and the international community expects a world power to intervene in some cases. Being big brother has responsibilities.
Of course China is not in Africa to be in charity. They want to trade. They made vast investment there. They want to protect investment. But they not there to push religion or push theri moral or ethics or impose thier system on the Africans. So, maybe China will do a better job than the West...i dont know. Maybe China will do better because it has been under the receiving end of colonization for so long.