The problem, as this article describes it, is that Chinese immigration to Africa is sponsored by the Communist Chinese government, as contrasted with the diaspora of Chinese immigrants in other parts of the globe.
There is an agenda behind this; a form of neo-colonialism wthout any of the western virtues (and there were many) that accompanied the 19th Century colonization of Africa. That colonization included missionary efforts which provided schools, hospitals, and impartation of the western worldview.
Many will say that that effort failed, but the aspiration for human rights are being played out in Zimbabwe today.
What do the Chinese offer ?
Great points. I think at most they offer economic growth. As bad as things are in Africa, that is worth something. Hard to expect Chinese to offer values. Perhaps organization and hardwork. We shall see.