Well, ... you still don't explain how they will know what's in their neighbors pantry. Hell, many neighbors in the city barely say hello to each other much less show an interest in each others lives.
An adequate national supply means little when most emergencies occur on a local or regional level. Forest fires, earthquakes and floods have been known to trap people for weeks at times, being prepared lessens the potential for disaster. As proven time and again by history, relying on the government to rescue us in a timely manner is only wishful thinking, so I prep. An adequate stock inventory today doesn't necessarily translate to tomorrow, especially if there is a workforce breakdown along the supply route due to illness, ... putting off what is easily had today for a later day is usually identified as lazy, procrastination, or a lack of care. Of course, funding may be a concern for some, although that's not really who is being addressed here.
I don't need to answer your question about what i'd do without food or water for a week or more as i've done my due diligence and prepared as earlier explained, and yes, i'm prepared to defend my home from attack if necessary, but at this point that's far from my current expectations and more in line with worst case scenario.