Your run-of-the-mill shoe stank might not pose much of a survival threat, but trench foot certainly will; baking soda is great at absorbing the moisture that might otherwise literally cause your feet to rot off your legs. As for the health of your teeth -- it will be pretty hard to get through your day's rations of homemade jerky and hardtack without some high-quality chompers. And you certainly don't want to rely on that pesky fluoride that will "kill your brain over time" (um, what?).
Interest in the movement picked up during the Clinton administration due in part to the debate surrounding the Federal Assault Weapons Ban and the ban's subsequent passage in 1994. The interest peaked again in 1999 triggered by fears of the Y2K computer bug. Before extensive efforts were made to rewrite computer programming code to mitigate the effects, some writers such as Gary North, Ed Yourdon, James Howard Kunstler, and investments' advisor Ed Yardeni anticipated widespread power outages, food and gasoline shortages, and other emergencies. North and others raised the alarm because they thought Y2K code fixes were not being made quickly enough. While a range of authors responded to this wave of concern, two of the most survival-focused texts to emerge were Boston on Y2K (1998) by Kenneth W. Royce, and Mike Oehler's The Hippy Survival Guide to Y2K. Oehler is an underground living advocate, who also authored The $50 and Up Underground House Book, which has long been popular in survivalist circles.
Earthquakes, tornadoes, and hurricanes can cause you to leave your home or even be trapped there. Roads could be blocked due to fallen trees, power lines, or even damaged earth from the natural disaster. Rescue crews can not be in all places at once. You may have to wait it out for quite a while before its over. You won't be able to go to the store or to the corner market.