There is a difference between not ever touching a gun, and having unfettered access to one. In this story, the 12-year old had easy access to a gun, which turned out to be fortunate in this case, but this case is the outlier, sort of like saying that you don’t wear your seatbelt because you have heard stories of people who were saved by being “thrown clear”.
I first handled a gun at somewhere around 12 or so, in Boy Scouts. I didn’t get to take it back to my tent, and it was under constant supervision by at least two adult instructors at all times.