On another thread on this forum there is a discussion about the civility that is occurring with all the power outages and the only example of violence was NYC in 1977. NYC in 1977 [year of Son of Sam] there was violence everywhere, not just during the power outage.
I have friends in Baltimore right now, most of what they are doing in the outage is sweating and cutting trees for others. Today she posted a pic of her flying a 172 over the Bay as a bit of R&R.
But back to my point...Katrina is not, by itself a gun carrying event [unless the "what kind of sidearm do you carry to protect against a hurricane?" thread exist], but you are correct the SHTF CAN occur after that kind of event. But most folks, the statistical vast majority never, ever see that potential for violence. So for that majority, the need to carry a weapon daily is an abstract consideration.
And there is certainly no reason to label them "libtard" or "ignorant" because they made their decision. I know many conservatives who choose not to carry for any number of reasons and I know folks who are excruciatingly smart who draw that conclusion. Adversarial labeling does nothing to move the ball on either side. As far as changing minds...I have found, through personal experience that I don't change minds demanding my rights but have better luck fully understanding the reasoning behind the objections that others have and letting them see through my deeds what I am, rather than telling them what I am.
To be honest, I see no reason to open carry, but that is MY personal opinion only. As others have pointed out above, it leads to issues that do not need to come up time and again. Sometimes, like it or not open carry perpetuates a negative stereotype. An interesting example. Last year an open carry group in Lexington decided to have a Lexington Open Carry Adopt-A-Highway Litter Pickup on a pretty busy section of a four lane highway. The idea was to show normal folks doing normal stuff to remove the stigma of open carry. It didn't work out that way in the public perception. It was an idea that did not work as hoped. Perception is well more than half the battle.