The decision to sacrifice personal gain or even just to abandon the comforts of conformity in order to do some work that bucks the wide and deep trends of depletion and annihilation comes from an unusual place. It is not done for gratitude since only human beneficiaries can even say thanks and they will have no resources to materially return the favor. People who must thank themselves or wait for thanks will burn out. True reformers are more likely to be burned at the stake, or worse, ignored, than to be welcomed for their proposal to rearrange the plumbing of money, effort and value that operates a society. I suspect such decisions arise from unusual identities, from an uncommon perspective on what a person is and what people are and how linked those two may be, from an ease of seeing "us" and a difficulty of seeing "them" whether class, nation or generation is the presumed distinction.
Almost anyone is smart enough to change the world for the better. Few are brave enough and fewer humble enough to work at such changes for greater reasons than their own satisfaction. So perhaps the portion of us who tithe and then the portion of those tithes that actually bring relief, hope or justice to some living thing...perhaps that is the best we will ever do. Still, at any moment any one of us could choose to swim against the ubiquitous current of people who , under the illusion of self interest, find it easier to default for contentment and change the world for the worse one hamburger at a time. That magnanimous choice would be an act of great faith. How few would it take to cancel empires of ambition, to suck all wind out of the sails of the schemers?