Why should we want to be servant leaders even if we are not compensated by it?

We want to be servant leaders even if we are not compensated by it because of public interest, common good, and advancement of society that we live in. Because of our children, their children and children's children. We want to leave something behind that can't be deleted or measured in money/material gains but in the sense of better life for all people. That kind of reward, remembrance of leader and his/her works for decades to come, is more honorable and precious than any money. Why? Answer is simple: many generations after can learn from that work and continue to do it.