That's what they should have done. Teach these people basic things like sanitation, rule of law, and freedom, rather than giving them aid constantly which does nothing but fund the tin-pot armies and keep the people poor.
And if the Africans would have rejected the help, then screw them and their resources. Let them stew in their own feces then.
Some African countries were well on the way to becoming developed nations when the leftists prevailed on the colonialists to abandon them.
Most have gone regressed back to tribalism, and are in worse shape than they were under colonialism.
They mostly did not give them free aid. That is what happened after the colonial period.
Don’t forget that the Africans themselves were exploiting each other for all they could get.
Nearly all African slaves were enslaved by other Africans before they were sold elsewhere.
Actually, the Europeans tried to do just that.
But in the end, Africa always wins.