Mr Don said: ‘Self-sufficiency, I have to tell you, is a non-starter. At best it consigns you to a life of dreary repetition and terrible food, at worst your teeth fall out, your breath stinks, you erupt in boils and you sink into 13th-century malnutrition – The Good Life indeed.’
but he doesn't say why your teeth should fall out and you would get boils; he doesn't go into what vitamins would be lacking (or why they should).
I am not advocating self-suffiency but he doesn't give any facts or proper reasoning to back up his assertions.
However, anniebach, yes, weather dependent, and it is very difficult to get rid of predators without some kind of help; organic is good but not easy to produce on a large enough scale even in a large garden. I suppose one could get plenty of manure from the house cow.
You would have to set up some form of bartering, too, unless you made your own flour, grew rice, kept sheep for wool, grew cotton for clothes etc, kept bees.