Switchblades are illegal in many states because hoodlums used to use them in movies long ago. It makes no sense to surrender our liberty because of something depicted in a movie.
Butcher knives and swords are far more dangerous than switchblades. The vast majority of gun deaths come from handguns, not assault rifles. But in movies, most deaths occur by fully automatic assault rifles and sub machine guns. It is peculiar that many Hollywood types want to outlaw guns yet see nothing wrong with pretending to shoot a dozen people in a film for trivial offenses.
It is true that having more guns in the world results in more unintended shootings. Having cars and hammers in the world results in the same effect. Another thing that greatly increases the number of people killed by guns is the depiction of people being killed by guns on television and in movies. I would say that making it illegal to show someone being shot to death in film would stop just as many shootings as outlawing all guns.
When you suggest erasing the First Amendment in this way the actors who want to outlaw guns and erase the Second Amendment suddenly get interested. If they could only understand that the way they feel when we discuss outlawing a freedom they hold dear is exactly how a gun owner feels when they discuss outlawing the freedom they hold dear.