If someone wants to own a nuke, and has ill intent, and can afford it, does making it illegal prevent them from owning one?
What about letters of marque which authorized basically privately owned warships?
The issue isn't people, good citizens with morals, principle and honor from having ANY sort of weapon. The issue is when immoral unprincipled, dishonorable people getting any weapons, and they usually are not deterred by laws. Our biggest mistake is usually to assume government always works within the constraints of morality, principle and honor.