In a society where everybody has and carries guns, or simply keeps them in their homes, guns cease to provide some kind of defensive advantage.  The security playing field becomes level.  

There is no emotional or psychological security in this, either.  People will become and remain frightened, not being able to know the intentions or ethics of all the people around them.  Frightened people will react defensively, using their guns even when there is no threat.  Others will be required, then, to use their guns to defend against that very real threat.  It will be a blood bath.  

Making our world and communities more dangerous, rather than less dangerous, is a stupid thing to do.