No they aren't missing any points:

Guns are made to Destroy/Kill/Inflict Damage so that when someone decides to Destroy/Kill/Inflict Damage they can do so Effortleslly. It works both ways: The ones that was to Destroy will be met with their own Destruction by equally proficient tools as theirs.

The caveat is that should people wish to act in that way therefore people can appropriately respond. It's you who I think doesn't understand what guns are designed to do. Guns are designed as the Proper Means to Eliminate or Neutralize Threats. Therefore Guns are Designed to Protect Life.