I think that many see the "new" terrorist threat as something completely different from what we faced before. The idea that all terrorism is either "over there and we don't need to worry about it" or "so overwhelming that unless you have a tank, hospital and bunker in the hills of colardo" is pervasive. Certainly if you are within the immediate effect radius of a conventional explosive, chemical attack, bio attack or nuclear attack you may as well "kiss you a$$ g'bye". OTOH, if you are in one of the ever widening circles of evacuation that will be implemented in such circumstances (which, BTW are identical in nature if not geography to the evac plans that have been on the boards for atleast 5 decades for storms, quakes, hazmat spills and nuke attacks) you will want some supplies to make the evacuation somewhat more manageable and comfortable.

If I were selling gasmasks and tyvek suits I would PooPoo the bob because you must either buy my gear and be able to survive the holocaust or die.

If I were selling Underground bomb shelters in the hills just off the interstate then I would PooPoo the Gasmasks and tyvek suits because you will either get the news in time and evacuate or die.

These are marketing statements. Truth is Gasmasks, tyvek suits, Big SUV's, and bomb shelters are all part of a continuum of preparedness that will increase your chances of being there when the sun rises over the carnage left behind. Could be that having a gasmask in you desk drawer is exactly what you needed to get to the SUV so you could drive home and pick up the BOB before the Natl guard closes the roads between you house and your bomb shelter. OTOH if you are unwitting victim of Bio attack and then implement a BOB scenario driving several hundred miles (stopping at convience stores along the way) to get to your hideout then you have become the dispersal mechanism needed for the effectiveness of the bio attack. (Bad you!) and you will probably have managed to leave behind the area where the immediate response will be using up all the available supplies that are required to help you survive the immanent collapse of your internal systems. But Hey, you didn't know that the event had already happened because the aerosol in the ductworks is impossible to detect until folks start showing up dead or nearly so at the hospitals.