Charity grunt work brings forward compassion, acceptance, frugality and other qualities that wouldn't arise from working in finance. If you don't see the problem up close you won't want to donate 90% of your income.
Furthermore, smart people with the conviction to solve the problem and the guts to get their hands dirty eventually accomplish great things. Norman Borlaug comes to mind.
That's the bit that gets missed. Smart Stanford grads might not be initially effective at doling out food, but sometimes their smarts can do a lot more for their supply chain or donor base than their future cashflow from a conventional job.
Its pretty clear that a person who would dedicate their young years to charity work, already have those qualities. I'm thinking she might have retains some fragments of that, as she worked at her real skills and donated significantly.
That's like saying: "Anyone who would want to go to the gym is already pretty fit, so they don't need to go to the gym." The emotional muscles of charity need a workout just as much as our physical muscles. If you don't exercise them, they atrophy.
I agree she would she would retain some fragments of that, but she still could be substantially changed. See vacri's sibling (cousin?) post for an anecdote.
