I actually think you make a solid point. So many people don't know precious metals these days (they'd take a Hershey's chocolate bar before they took a silver bar), and place value in paper alone. How can one deal with those people?I believe you underestimate the amount of stupid in the world.
And yet, I suppose I think that people learn what is important to them. Now, paper is important...and people know paper, even the most stupid. If paper becomes worthless, and metals retain value, then those people will learn the value of silver and gold.
Also, I don't prepare solely for total breakdown of civilization. I prepare for lesser disasters, such as the mere breakdown of the dollar. In the case of the latter, gold may yet still be more valuable than grain. If not...I've always got my grain as well, since I do indeed have diverse holdings!