all of this stuff has nothing to do with colonialism, rather the attitude of the locals that grabbed power afterwards. Nigeria, Zimbabwe - both have an embarassment of natural riches, both utter ****eholes due entirely to the locals, not the British.
However I have spent some time in Accra lately, hardly a million miles from Lagos - also ex colonial, nowhere near as naturally wealthy, but generally a thoroughly nice place in a thoroughly decent country.
There is a limit how long even the PC brigade can blame the empire for all the current
ups.