Africa is an enormous place, yes there were terrible atrocities. But is a varied picture and some of the colonialist did amazing work. You can't compare Cromwell to what happened in Africa. Africa is a region where there was vastly less European influence. For example the vast majority of African arable land was never farmed by Europeans. Anyone who equates the British army of the 1950s to ISIS is a moron.
Anyone who defends clear-cut war crimes is a moron.