What is the most likely reason europe did not invest in education in its african colonies?

The main reason why the European countries did not invest in the education of the population of their African colonies was that these colonialist countries never had in view to include these colonies within their main territories, but rather they only sought to exploit their natural resources and use their populations as cheap labor. And as the populations without education are easier to exploit, and those who have no education hardly claim for their rights, the European colonialist countries did not invest in the education of these African people.