Regarding the comment "and don't just tell me you need the money", why would their personal financial situation matter if the person has already proven their skills and abilities?
The only other motivations I can see as being viable as a response (other than working because you have to earn money to live a certain lifestyle) is "I really want to learn XYZ and I can't do that on my own without working in a team with more resources" or for NGOs hiring there could be further social good motivations.
The only other motivations I can see as being viable as a response (other than working because you have to earn money to live a certain lifestyle) is "I really want to learn XYZ and I can't do that on my own without working in a team with more resources" or for NGOs hiring there could be further social good motivations.