I think most people are doing the best they can in a really disorienting situation. We were just at the grocery and all the milk was gone, in our largest grocery in town. All the toilet paper was gone yesterday and today in three stores. There were limits on items that were no longer available, anyway. All the flour was gone. So people are trying their best to think of how to feed their families for a month if all the stores close as quickly and unexpectedly as the schools and the library and my husband's doctor did.
A lot of these survival skills have been forgotten, or no longer taught, like do I buy canned milk so that I can bake? etc.
As to ammo, I'm not prepared to shoot someone over my supplies so I'm not going there. But I know my neighbors have guns and would use them on someone who came to take their supplies. They are mostly ex-military and have a "don't mess with me" attitude. To each his own.
As to people who got sick unexpectedly with a disease they had never heard of--well my heart goes out to them. What a terrible thing, and I wish we would minimize some of the inevitable scapegoating that is starting to happen. The first case in Maine was id'ed as a middle aged woman who had recently traveled abroad. Class privilege etc. comes to mind. Turns out she was a Navy reservist on Navy manuevers.
I say we stop blaming them and work on keeping as many folks safe as possible and try to remember that they are doing the best they can, even if it in hindsight is clear to us that they did something that they should not have.
And calling people stupid because they want to buy toilet paper--well, I'd rather stop judging and try to keep a helpful, positive mindset.