The same thing happens to expats from third world countries, single motherhood is extremely high in the third world, young men decide to study hard and get out from the third world and people there believe they owe their countries anything, many of them actually feel allienated since in their home countries they were unable to get a wife nor gf because some men impregnated multiple women and ruined it for them, why should they contribute to their socities where they were even unable to form a family?

And people still believe this men should return to their countries to help them develop, why should they? they have a better quality of life and they also managed to get a wife or gf in 1st world countries, a thing they would be unable in their home countries given the extremely high percentage of single mothers.

If we are unable to get family or children in our countries, we dont owe them anything if we leave, if Elon Musk can end poverty in South Africa and he simply doesnt want to it is his right, he owes nothing to South Africa, if South Africa wanted Elon Musk to use his fortune to help them, it should have not allienated Elon Musk, it should have done more so he could have a wife and a family there, but it didnt and now people are surprised Elon Musk gives a shit about South Africa.

If he wants to use his fortune in space travels to mars rather than use it to end poverty in South Africa he is in his right, he earned it so he deserves it.