I've been something of a misanthrope since I was old enough to see what havoc and devastation our species was wreaking on this planet, but I still care when people are hurt and suffering, and the bullies, sociopaths, and sadists who run almost everything piss me off to no end.
We fight. We fight for those who will have to inherit the world we leave them. And we fight for all the the other species who have the misfortune of being stuck on this rock with us. And if nothing else, we fight to spite the powers-that-be, because to hell with every last one of them.