Because there's too many internet commandos who come up with this kind of stuff and then push themselves off as some kind of expert. When they've never been in the military, never done any serious training, and never trained a single person. They sit in their basement and imagine something as fact then go around spouting it off until they get some other unknowing person to believe them. Then the myth is continued until to unknowing masses accept it as fact without ever knowing a thing about it. And those are the internet commandos. Gun shows and gun magazines are full of them. They become 'experts' not because they actually have done anything or know anything but because they claim themselves to be 'experts'.
