Question

account for the failures by post independence african governments to implement rural development strategies

Answer 1

Why? The question presupposes that this is a surprising fact. But since sub-Saharan Africa has not exhibited a single example of a government that successfully develops its rural areas in all of recorded history, both before and after the decolonization wave of the 1960s, I would say the surprising fact is that anybody would have expected anything different. Indeed, this question may contain Eurocentric roots that fail to comprehend that African cultural traditions of government have different aims and philosophy than European.