The abusive history of the Zulus is well documented. Why do you think one assegai wielding tribe so easily caused havoc in Africa ?
Travel to the rural parts of the Transkei etc today. You will find people not living much differently to 200 years ago until recently when the government gave them western housing and electricity. But in the 80's and 90's I went there often and found the most peace loving , friendly, happy people with a rich culture of respect and dignity. Not all of it is easy for the western sensibility to assimilate. Labola and ancestor worship etc. But none of it intrinsically dark or evil. People who lived and loved and cared for each other. Good people. I think this is pretty much the way Africa existed for centuries. But if your imagination wants to paint it as all about blood and rape, then again feel free to be victim to your own indoctrination and prejudices.