(short answer) The amount of money wasted to enforce this would save more lives if donated to sick children. (long answer) Utilitarianism: the ban is too expensive to do and the resources are better allocated saving lives elsewhere. (natural rights) People should have the right to own any type of gun unless the case can be made against their competency. (self-interest) Depends on what you value more liberty or security. (notes) there is no such thing as an assault weapon, it is a made up term to describe a scary looking gun.