It seems to me that people who do a lot of good in the world tend to work on a specific cause which is close to their heart (Martin Luther King, Gandhi) or do professional work that helps a lot of people solve a particular problem (Borlaug (the Green Revolution).
In addition to your point about motivation (which I agree with), getting too abstract discourages people from getting the advantages of specialization.
It seems to me that people who do a lot of good in the world tend to work on a specific cause which is close to their heart (Martin Luther King, Gandhi) or do professional work that helps a lot of people solve a particular problem (Borlaug (the Green Revolution).
In addition to your point about motivation (which I agree with), getting too abstract discourages people from getting the advantages of specialization.