It's racist and divisive for the same reason. His work mutes the response of the violated and the perpetrators remain an invisible, abstract, almost glorified presence. It objectifies a whole race and history, to the point the message is "lost in lamentation". It is not history being depicted but events that people still have to deal with today.
The Barbican has given credibility to an offensive and racist installation, disguising itself as art. [Racism: having or showing the belief that a particular race is superior to another].
The artist says he wants to educate and challenge. His attempt is arrogant and lacks the clarity of experience. The most likely people to visit this exhibition will be the repugnant voyeurs and the misguided intellectuals who want to give this disgusting work validity and spout nonsense about how important it is. The curator has no direct and firsthand experience of racism and the residual affects of being continuously identified with this abhorrent history. People will be moved temporarily and then continue with their lives. Very little of their racial prejudices will change.
Just a thought but...would it not have been more challenging to turn the context on its head by having white/ Europeans in place of the black /Africans; now that would require some critical thinking by shifting the perspective and challenge how we all identify and confront the subject matter?