Because people think only about themselves, perhaps not all, there are those who are willing to help make the world a better place.
I am not against the desire to make money. This is normal. I personally like that people have chosen for themselves the opportunity to earn money and in parallel with this they will improve the ecology on the planet.
Money is not superfluous, because then they can put it on the agenda of the project itself, make it even better for its clients.