You missed the point. Widespread gun ownership among non-criminals has side effects that harm innocents. Not the case with encryption.
You could argue it makes it easier for people to become criminals, but even that is a weak comparison. Guns are a lot harder to come by in the UK (for example) than encryption software would be in a more regulated world.
You hid the point pretty well then, because those who engage in "domestic violence" and "fights that escalate into _blank_" are certainly not "non-criminals". So that leaves only accidents:
Widespread $PHYSICALOBJECT ownership among non-criminals has side effects that harm innocents. Not the case with $VIRTUALOBJECT.
You know that regardless of what you use for $PHYSICALOBJECT or $VIRTUALOBJECT that statement will be true right? You also did not state exclusivity among non-criminals, is that because you know that is impossible? If that is the case then you've hidden the point very well.
You could argue it makes it easier for people to become criminals, but even that is a weak comparison. Guns are a lot harder to come by in the UK (for example) than encryption software would be in a more regulated world.