That's a huge fucking stretch. African countries, Mexico etc suck so bad because they are corrupt to the bone, nothing else. Most countries have suffered through imperialism to some degree - that's a shit poor excuse. Fuck - we dropped Atomic bombs on Japan less than 70 years a go and they are a dominant economy.
I do agree that if you can make it through an atomic bomb you can make it through anything. However I don't think you can compare bombing one city in a country which already had an established economy to demoralizing an entire continent and socializing them (since this took place over hundreds of years) to feel like they have no upward mobility.
Yes those countries are corrupt but only because there was no infrastructure after the imperialist nations left allowing corruption to move in.
I personally believe that every human being has the capability to make a better life for themselves so this particular theory (which a lot of people believe) makes a lot of sense to me.