IMHO I think the instructor “SHOULD” be armed. The gun on their hip is a tool and a teaching aid. For those who teach concealed carry it is a demonstration or proof of concept. It should never be part of the curriculum other than for a conceal-ability demo. The pistol is not there as a dominance object but more as a deterrent, a defense and dare I say as an object lesson for those that are skittish about handling fire arms. I have received multiple comments about how naturally I carry one was young lady that was very matter of fact “You wear a gun like you wear clothes, it fit’s you, you don’t adjust it, check it, pull it out, fiddle with it it’s just there. No more or less than the pants you are wearing. I want to learn how to do that.” She was a research scientist for a big pharma company (think Bones the woman on the TV show but blond) and she was terrified of guns.
To those of us who do carry regularly and attend a class it is a pacifier in that “OK I trust this guy/girl to teach me and he/she is armed; I am now unarmed, but my teacher is armed, so I am (mostly) OK with being unarmed, now I can concentrate on what they are teaching me.”
While I get the safety aspect and agree, I also get the apprehensions of my students when I teach that level of class. The key is risk management but some folks forget that some risks are external and need to be addressed as seriously as slipping a live round into a class.
JMHO and worth what you paid for it.