European colonialism was extremely, horrifically violent. It left a legacy. Not that there wasn't violence in Africa before colonialism, but the level of violence there at that time, before colonialism, was similar to the level of violence at that time around the world, no worse. America was not 'settled' by the Europeans without horrific violence.
Yes, it was. In some areas it was truly horrific. But you ignore the likewise incredibly violent past of the pre white contact Africans. Life has ALWAYS been cheap in Africa. The black population didn't need the slightest help from the white man to inflict horrible crimes on their fellow people. They were quite conversant with mass murder long before ****** ever showed up. All the white guys did was educate them how to murder in a more civilized way. Instead of hacking them to bits with machete's (like was done to 900,000 in Rwanada not too long ago), or how the Inkatha Freedom Party (made up mainly of Zulu's) stabbed almost 1,000 ANC members to death with their very brutal, yet traditional Assegai, they can use guns. Every bit as deadly, but at least the victims don't linger like they do after a machete attack.
No, you ignore the systemic, and endemic violence that is part and parcel of life in Africa, and which has ALWAYS been a part of life, and death, in Africa.