Two, a person may not ordinarily feel a need to carry a gun for self-defense — but something happens, and there is no time to obtain a permit. You would then have to choose between breaking the law against concealed carry, or carrying a handgun openly for self-defense.
Three, picture this. You might be visiting a state that does not issue permits, or that makes it so difficult that you are unlikely to apply for a permit. Under those circumstances, it might be appropriate, under some conditions, to carry a handgun openly for self-defense. I would hope that open carry in cities would be infrequent because it is so disquieting. Please: spend the relatively modest amount of money and time required to obtain a concealed handgun license now, if at all possible.
What ticks me off about some manifestations of the open carry movement, however, is the second goal: the delusion of “normalizing” open carry. This is about as likely to work as “normalizing” homosexuality by having two guys strip naked and have sex in the middle of Main Street. Guns are powerful symbols — and even those of us who are strongly pro-gun, and support widespread gun ownership and carrying, respond negatively to unnecessary displays. You can imagine the reaction from those who are ambivalent or even slightly hostile to gun ownership.
A handgun is primarily a defensive weapon: something that is easy to carry and easy to put into action in the event of a sudden and unexpected attack. By contrast, a shotgun or a rifle is primarily an offensive weapon: clumsy to carry, slow to bring into use. There are circumstances where you might have occasion to carry a long gun while going around town — but almost all of these scenarios involve flesh-eating zombies. No surprise, then, that the reaction of most people to a stranger with a long gun in a public place is concern, if not outright fear: “Is this guy a lunatic who is going to start mowing people down?”
If you need to carry a gun into a public place, and there is some good reason why you do not have a permit to carry concealed, then going for discreet is a really good idea. Consider something small and black that is not going to scare the wits out of people when you walk in the door — like this Walther PPK, or this Colt Mustang. If you are carrying a gun to make a political point — and especially if you are carrying a long gun into the children’s section of the public library — well, you’ve succeeded. You’ve convinced everyone in the library that your pet issue is more important to you than the peace of mind of every kid and adult present.