I disagree. The issue is that for production of food and energy, we still need labor. A lot of this labor is low-paid (supermarket workers, truck drivers, fruit pickers, butchers ...). If you make food free, you won't be able to motivate these low-paid workers any more, so noone will work on food production, so food production won't be free any more.
It used to be 90% of the population was working to produce food, now its around 1% and decreasing with increasing efficiency. So it is an increasingly negligible amount of labor needed to provide an already surplus amount of food.
It is cynical and ignorant to assume the dollar is the monotheistic deity of motivation for everyone. There are and have been countless cultures across the world who don't require monetary payment to produce the requisite food for the community.
