Awww...sorry. I've confused people with my posting style a couple of times recently.
So, my pithiness aside, and with my serious face on...
I completely agree with you. To think that people will take actions fully cognisant and caring of their actions on all around them, without a substantial percentage of them acting in their own self interest seems to fly in the face of my varied experience in this world.
Some will do 'the right thing' for sure. Heck, be optimistic and say most. But even those folk will disagree about what the right thing is in many circumstances. And some will act in self interest.
I'm unsure what long term successful society has run without laws or strong customs, and a body enforcing them in some manner. And unsure why anarchists seem so dismissive of that fact.
Idealism is good. But without pragmatism it's just dreams. Anyone with experience implementing anything knows how important visionaries are. But equally, they know how much effort it takes to turn vision into even a bastardised reality.