I'm 100% for open carry, but who honestly would need to open carry a decked out AR-15 or such. Not trying to boil the water here, but that's a bit over kill for exercising your right for open carry. Honestly I would see that as a "Hey look at me" kind of deal. Were trying to get people comfortable with open carry, not make them think were preparing for a zombie attack.
Rights are not concerned with excuse, justification, or demonstration of need. Rights are concerned with the assurance of self-determination. Until you stop thinking of rights as privileges we ought to have, and understand them as liberties which inhere in our very existence and which can only be restricted, not granted, you'll be vulnerable to the assaults of reasonable-seeming arguments which would deny you life and liberty. "Because it's up to me, not you" is the purest, unassailable answer to "Why?"
Now, with regard to normalizing the possession and bearing of firearms in modern society, there are certainly behaviors that don't seem particularly strategic. However, it is critical that we don't resent those who engage in them, or we do not respect their rights, rather our hearts seek to deny them liberty.