Boredom is a powerful motivator too.

A couple months of laying around doing nothing will drive most people crazy and they'll begin asking themselves what they want their life to be about.

And even if they don't contribute anything, should all people be required to useful to others or can't some just choose to be left alone if they are self sufficient?

In a world of scarcity I can see the argument of forcing people to contribute if they want to take back but what about a world of abundance? You and I are breathing abundant air, for free, and nobody is getting angry right? What if other resources like electricity were as abundant as Tesla once dreamed?

I'm not saying I'm right or wrong. These are just thoughts worth consideration.