I suspect the reason is that many of these "reporter" types are just recently being exposed to the increasing commonality of carrying arms for self-defense. For those who have little to no prior experience, which I imagine is most of them, they are open to misinformation and it can get quickly colored with biases. So we hear them use terms like clip instead of magazine, bullet instead of cartridge, pistol when the gun is a revolver, and "shoot to kill" instead of shooting to stop. There are likely a lot of mistakes in their research (that done for them) and their note taking which they believe is correct. This video had one glaring one about Virginia.
The problem is, a good deal of the population which is not part of the gun culture, and even some that are, take what these reports say as gospel and that is how erroneous information gets spread.