Lots of people are obsessed with a hobby to a degree which is borderline unhealthy. Borderline unhealthy doesn't mean unhealthy, but it does mean it's taken over your life to a significant degree. Some of us with those hobbies manage to convince ourselves that there's something unique, something special, and something truly important about that hobby. It's a way to justify the fact that, you know, it takes up a significant portion of our lives.
Gun nuttery is just a hobby like any other, except for the fact that it involves a killing machine.