We are not discriminating against Africans, we have Hukou even for our own citizens. It's a we have too many people and our country is still poor yet we do try to provide services. Too many mouth, too little money. So it's evil, but a necessary evil.
Also people from African countries are not bad people, but due to the difference in culture and customs, they don't seem to care much about the law in terms of petty offenses. In China law is the law, and it is obeyed to the letter. Hence Africans can feel safe in China, and anyone can feel safe walking at night or anywhere.
Drugs may not be a big deal in Africa, but in China, it's a big deal. I can see how someone from Nigeria wouldn't understand, just like if a Chinese were to go to Africa, there is also a divide.
I just read the comments on this video, damn those are some racists crap.
Chinese was welcomed, well allowed, or we are at least in every corner of the world, when our country was crap, so now we should accommodate others as well, but here's the thing, you have to be patient, China is still very much a developing country. And one with 1.3 billion at that.