All good points, and there are situational considerations as you and others point out. Dehydration for example; where I live, I am far more likely to drown than die of dehydration. Even rudimentary purification equipment would prevent dehydration in most of this state. Remember too that peanut butter is about 50% carbs and 50% protein. Two Tbls of PB spread on an ounce of hardtack or bannock, the carb content about triples to 75% carbs/25% protein.

I'm not a doctor or a nutritionist. The main point of my original post was that PB is portable, shelf-stabil, and provides a whole lot of food energy and flexibility at less than 20% of the cost of similar calories in those coconut food bars.