There is huge lack of logic in this set of sentences. Referring to what the different instruments have been invented for we can say that:

- gun == instrument for killing (or at least it was invented for this)
- pencils == instrument for writing
- pencil !== instrument for miss spelling words
- cars == instruments for transportation
- cars !== instruments for driving drunk
- spoons == instruments for eating
- spoons !== instruments for making that lady fat

In other words the proposed metaphors hold for things the cited instruments have not been invented for. Following this logic a better premise should be something like "If guns break windows, then....".

Interesting example of own-goal shirt