I believe that weapons should not be accessible to all. The human thirst for power can provoke the use of its weapons for very different purposes that will harm society.
The U.S.'s 2nd amendment recognized just this phenomenon and attempted to deal with the problem by giving society the tools to fight back if it became necessary. An armed population makes it more tactically difficult to perform certain governing operations such as genocides and population displacements/replacements.
The downside is that in response, those who 'thirst for power' have shifted to more subtle methods than, say, old uncle Joe Stalin. Don't forget to get your flu shot.