While our examples certainly lack the true depth of the topic... I can see what you mean... and would agree that if nutrition were the ONLY desired outcome, the nails would certainly be unnecessary.... but it's easy to push aside the "teaching value" intent of eating the nails because it is such a simple concept. Death and our mortality are certainly a bit more complex than what we've both offered.
I just still don't see any way (other than intellectually) for man to TRULY confront his/her certain death.... and think you would agree that the intellectual concept of eating a nail-sandwich (rusty or otherwise
) would NOT impart the
same benefit of teaching that actually eating the sandwich would.
So, I still can't grasp the "pointless" part of your argument.