"There's no reason why that continent should be on par with Europe, N America or Asia. But, the introduction to the modern world came at the hands of colonialists who did a bad job by and large. Dutch, French, etc. Many didn't achieve their tenuous independence till the 60s."
I think you're slandering the Colonialists. The Africans they encountered were practically neolithic savages. Including places like Timbuktu, Zimbabwe, or Zulu cultures that are raved about. I rate these places on a par with the murderous Aztecs in Mexico. Even today, with the Europeans removed, they butcher each other in the millions. You can't blame the Colonialists for that anymore! In fact, the only habitable places in Africa are those areas that still have vestiges of European administrative organization and minimal contact with the West. And we see the Africans doing everything they can to destroy what is left of that worthwhile legacy!