As a specially trained valuable first world labourer -- at least, my employer seems to think I'm worth a salary -- I find growing my own potatoes (and a few other things) a welcome break from my desk and screen.
I'm sure my garden is nowhere near as efficient as a real farmer could make it, but that's hardly the point. And a few rows of potatoes (even with my inefficient management), are a much more productive use of the land than a typical suburban lawn.
In my comment, GP is pjc50; not you. You literally said that everyone should plant potatoes, which I, and pjc50, disagree with. As I said before, do it if you enjoy it; it's not a great use of everyone's time.
I'm sure my garden is nowhere near as efficient as a real farmer could make it, but that's hardly the point. And a few rows of potatoes (even with my inefficient management), are a much more productive use of the land than a typical suburban lawn.