Another good point, Dave. I'm not advocating the prohibition of all or even most firearms--just assault weapons. Based on your logic, should every American be compelled to carry a firearm with minimal restrictions for convicted criminals and those with mental health issues, etc.?
The government could require training and possession of a firearm for all citizens over 18 (the military draft age) in order to receive or renew a driver's license or passport, for example. But we are already a gun-happy nation with over 400 million firearms circulating, and that's probably an undercount. And it appears that all these firearms have not made us any safer. Have they?