Who would you leave alive to teach the new generation the correct things? If they have to figure things out themselves it will end exactly the same. And if you leave teachers, there is a 100% chance that they will get murdered and it will end exactly the same.
The problems we have today aren't because humans aren't smart enough to figure things out. It's because humanity as a collective isn't smart enough, won't act smart in large groups. It is absolutely impossible to steer such a large number into the right direction. The bigger the number, the more people will focus only on their own in favor of the greater good. Just ask yourself: when have you last thought about the suffering of other humans without being reminded of it by others? When have you last acted selfless for people you don't even know? It's just not in the human nature to work like that. Humans can't possibly fathom global consequences, they can barely acknowledge consequences in their immediate surroundings, some not even that.
If you demand respect or gratitude for your volunteer work, you're doing volunteering wrong.
