When action is divorced from consequences, no one is happy with the ultimate outcome. If individuals can take from a common pot regardless of how much they put in it, each person has an incentive to be a free rider, to do as little as possible and take as much as possible because what one fails to take will be taken by someone else. Soon, the pot is empty and will not be refilled -- a bad situation even for the earlier takers.
What private property does -- as the Pilgrims discovered -- is connect effort to reward, creating an incentive for people to produce far more. Then, if there's a free market, people will trade their surpluses to others for the things they lack. Mutual exchange for mutual benefit makes the community richer.
Secure property rights are the key. When producers know that their future products are safe from confiscation, they will take risks and invest. But when they fear they will be deprived of the fruits of their labor, they will do as little as possible.
That's the lost lesson of Thanksgiving.