For global catastrophic risks the costs of food storage become impractical for most of the population  and for some such catastrophes conventional agriculture would not function due to the loss of a large fraction of sunlight (e.g. during nuclear winter or a supervolcano). In such situations, alternative food is necessary, which is converting natural gas and wood fiber to human edible food.
Again, the reason we tend to look sideways at those who get a little too into prepping for an apocalypse is because of their smug optimism. People actually being realistic about a dangerous future would be better served joining the military or ingratiating themselves with high-level government officials than agonizing about a little mouth scuzz or foot fuzz, right?
Further interest in the survivalist movement peaked in the early 1980s, with Howard Ruff's book How to Prosper During the Coming Bad Years and the publication in 1980 of Life After Doomsday by Bruce D. Clayton. Clayton's book, coinciding with a renewed arms race between the United States and Soviet Union, marked a shift in emphasis in preparations made by survivalists away from economic collapse, famine, and energy shortages—which were concerns in the 1970s—to nuclear war. In the early 1980s, science fiction writer Jerry Pournelle was an editor and columnist for Survive, a survivalist magazine, and was influential in the survivalist movement. Ragnar Benson's 1982 book Live Off The Land In The City And Country suggested rural survival retreats as both a preparedness measure and conscious lifestyle change.
Say you're at work and a terrorist attack occurs. Roads are closed to any and all traffic but you only want to get home - even if that means walking. You may not want to grab your full on family pack in the car or you may not even be able to get to it. But you just want a light kit to get you through. How far is it to get home from wherever you may be? This get home kit should provide for 1-3 nights of traveling on foot till you make it home.