https://pbs.twimg.com/media/E2xXMrwUcAABK7T.jpg There are more black people in London than there are white people living in Africa, not counting the one country of South Africa. That's a total area of 19,800,000 square kilometers, not even counting the Sahara Desert. The entire U.K is only 243,400 square kilometers, which is about 80 times smaller. Why do you think Europeans don't want to move to Africa, and so many who did live there decided to move away? Europe even colonized almost all of Africa once.
So Black people are 'Africans' now. Interesting. Let's see if any more racist, bigoted gems are unfolded in this thread.
Because (obviously) the statement is not going to still hold true if South Africa were included. So South Africa is excluded to try to help drive home a point, for dramatic effect. (There are simply almost no white people in almost all of Africa) There are actually a fair number of white people in South Africa. The reasons for this would involve a discussion longer than you would like to hear. A lot of them did leave after the end of the white-led government, but a lot of them remained too. (There are about 4.6 million white people in South Africa, which make up 7.5% of the country's population) South Africa referring to a country, not a large region of the continent.
What you are actually asking is why would someone care about a fact when they know it is not going to lead them to any logical conclusions they want. Which is why someone like you would intentionally choose not to think very hard about this to see any relevance.
In 1900, Europe had THREE TIMES the population of Africa. Today, Africa has TWICE the population of Europe.