I do not consider OC, in and of itself, to be the problem. The problem is inappropriate OC. Arkansas has not been an OC state in my memory, and our carry laws are currently in flux. I say that to explain why someone OCing a rifle may or may not raise eyebrows for me. If I were to see someone OCing a rifle at Mack's Prairie Wings, my assumption would be that the OCer is there to sell the rifle, or maybe have it repaired. Someone OC-ing at Home Depot, well, Home Depot doesn't buy, sell, or repair rifles, so that's "out of context." At that point, part of that equation would depend on how the OCer was carrying. AR slung over his back? I *might* (or might not) think that he or she didn't want to leave the AR in the car, for whatever reason. However, if someone walks into my local restaurant with a rifle at low ready, magazine in, that will send up all kinds of red flags for me. It's out of context and carried in a manner that suggests imminent use.
ETA: I'd also point out that the right to OC does not necessarily include a right to OC on someone else's private property.