It is vital to note that the absence of guns is not the absence of violence.
And to take the argument in another way:
You are a peaceful voluntarist, I imagine, me too. That means I won't hurt you, and you won't hurt me out of the blue.
Not everybody is like this. And if someone were to attack me unprovoked, why would I want a fair fight? I would want all the leverage I could have.
If you were in a fight with someone who's physically stronger than you and could beat you in a fist fight.....A fight you never wanted nor provoked in the first place.
Wouldn't you want a tool to level the playing field or overpower the opponent in such a way to end the fight before more happens?
A gun is that tool.
In most cases, guns are used only to intimidate and for that reason alone, taking this crucial protection away from someone who is physically weak or impaired is more than cruel.