You are a part of society. If something is bad for society, it will, in the long run, be bad for you.
If you look at the individual level, with a purely rational 'Homo economicus' rational actor, ideals don't make a lot of sense.
It's so programmed in we think baby lions are cute.
Lets say he has no global reach his choice may change opinions of the people around hom. It may even change minds on here.
“Hey, this boat is sinking. Will this one bucket of water I throw out stop it from sinking? No? Guess I’ll just do nothing then. Maybe I’ll pour some more water in. That’s the way things are going you know.“