A large number of donors assisted these countries and did so for a long period of time. What started as short term financial and technical assistance, developed into an institution. Institutions govern the rules of behaviour of those actors involved in the process and provide predictability. African governments and NGO's are part of the aid institution, like the donor agencies in the rich countries. This is true for so-called structural assistance or development cooperation, as it is for incidental or humanitarian assistance.
Aid is institutionalised - and bureaucratised.
Critics to the right of the political spectrum in the US do not like that. They argue that welfare programmes do not work in their own country and should therefore be cut. Look at those hooked on drugs, they argue. They are addicted and lose their individuality. Aid does the same, but on a collective level.