People who open-carry are probably more likely to actually be firearms hobbyists or enthusiasts than most concealed-carriers. The guns and rigs are often more expensive than the typical, non-enthusiast's pocket-pistol and holster (if he even has a holster.) In such hobbies, there does seem to be a certain level of "camaraderie", so to speak, like the way fishermen who encounter each other at the lakeside will chat each other up.
I drive an old 4x4 Jeep and an almost-as-old Dodge pickup truck. It's fairly often that someone else, driving the same as whatever I'm driving that day, will chat me up about it at the gas pump or outside Bass Pro. It was even more common a few years ago when I still had my 80s Toyota 4x4.
I don't live in an OC state, but frequent two of them (Georgia and NC), and used to frequent a third (NM.) In none have I encountered anyone so carrying. I can't say if, had I, I would have struck up a conversation with any of them. It's certainly possible.