because with a pen you can draw a sword.
strong = mighty?nopeop logic failed
mighty - having or showing great strength or force or intensity
i'll rephrase it. with a pen you can draw a gun and shoot the mother forgeter who tried to kill you with a sword.
With actions you punch the living crap out of somebody who tries to reason with you. With the pen, you can write potentially dangerous words that can destroy any sword-wielder.