The original article describes a phenomenon I have observed with frustrating frequency; most gun owners believe that their arms are protected while the arms of different sorts are on necessary or not protected by the Second Amendment.
I have found this most egregiously amongst the clay and trap expensive shotgun owners. To be charitable, they analogize the use to which they put their own arms, a highly social sport, to all legitimate use of all arms everywhere. To be less charitable, the discomfort they feel at people unlike them possessing firearms is exactly the kind of discomfort that drives gun bans politically.
They are not the only group to display this pattern. I have known competitive rifle shooters who can't quite wrap their minds around private possession of semiautomatic firearms. Perhaps they are so enthralled by the beauty and challenge involved in landing a single round precisely that other uses seem to distant in terms of utility.
Often, the deer hunter who shoots one or two dozen rounds per year with some friends does not consider himself a "gun guy" and does not see himself as exercising a right in any way connected with three gun competitions.
Although I read these sentiment less frequently now, I can remember 25 years ago reading articles by "experts" that maintained that a permit to carry should only be issued to the highly trained and subsequently state certified user.
Part of the preparation work for defending a civil right involves explaining to the people affected the nature of the right involved. Only if they understand that they all engage in a specific exercise of a broad and general right can they then come to understand that infringement of a specific exercise they may oppose is also an infringement of the right they share.