When poor countries who need assistance from developed countries are strapped with obligations to payback the assistance they receive, their ability to use the assistance as a springboard to improve economic conditions within their country is greatly inhibited. Furthermore, many developed nations have corporations that generate profits in a single year that are great than the gross national product of many developing nations, which makes taking back assistance funds seem greedy and selfish.
History has shown time and time again that poverty leads to a host of other problems. A poor nation is more susceptible to government corruption, military overthrows, drug and human trafficking, and environmental abuse. By helping poor countries, developed countries help themselves. Stabilizing poor countries can prevent many of the negative effects that will surely impact a developed country in the future.
Developed countries providing assistance to poorer nations sets a good example for the people of the developed countries; it shows that it is good to serve the poor. Developed nations have worked hard to gain wealth and sufficient resources, and now they can afford to give out of their excess to those less fortunate. It is a model that people in general should employ in their lives.
It is good that developed countries assist poorer countries in many situations. However, that assistance should always encourage eventual independence rather than creating a system of perpetual dependence. Giving back does not necessarily mean giving back in equal value, but it should be in efforts that increase the independence of the poorer nation.