I think that the main thing to understand, when trying to reconcile the diverse views present in the firearms community regarding open carry, is that custom does vary from place to place, and individual circumstances are different.
While I would be able to OC legally, it would create no end of problems for me. Because of my engagement with the community around me, there are hundreds of people who know me by name. Mine is a small community, with many people who are opposed to firearms ownership in general and carry in particular. I want to get along with these people, because there is more to my life than guns. With rare exception I carry all the time, and I nearly always carry concealed, so that I can choose the place, time, and manner of any RKBA activism in which I might become engaged.
Also, because OC is not customary here (Minneapolis area), it is likely that if I were to OC I would be asked to leave many stores and restaurants and would receive unwelcome attention from law enforcement.
I recognize that there are parts of the country where none of this matters, and if I lived in one of those places I too might well walk around town and go to church with a full size 1911 on my belt. When in Rome, ...
It's great to live in a state where OC is lawful, and I do see people around me who OC once in a great while. They run in different social circles than I do, and they make their choices.
I would urge people to think hard about their local situation before OCing. Consider what you're trying to accomplish and whether OCing serves your goals or not. Gun rights are a scope of conflict game, and the lower the public profile the firearms community maintains, the more success it has in Washington and in state capitals around the U.S. If you're going to offend many or most of the people you encounter, I don't think you're furthering the cause. On the other hand, if you're in rural Montana or some place where no one will care, Godspeed.