Are you willing to take a bet on what fraction of guns sold to civilians have been used in a homicide?

If you’re going to insist on a teleological argument, you might as well use the same standard we use for other tools: how people actually end up using them. No rational person describes knives as “tools to stab people” even though this is part of the historical basis for their development. Instead, the vast majority of knives are used to cut food or spread butter or open boxes. Indeed, these are all more plausible descriptions of what a knife is “for”, just like target shooting or hunting food is a much more plausible description of what guns are for.