The sign is not indicative of someone who personally does not want to use a gun. It is indicative of someone who wants to prevent me from using the best tool possible to defend my family, someone who wants to actively put my family in harm's way. I think someone like that deserves to have that sort of sign pointing at them. If you want to ban guns, you shouldn't have a problem with people knowing you don't have guns.
If you can't see the difference between "live and let live" and "hey everybody! I hope these people get harmed!" then I don't know what to say to you.
As for the kid/candy thing, I was pointing out the similarities in not liking people being jerks to their kids and people being jerks to their neghbors. Would that sign be as funny if some kids were physically hurt by someone breaking into their house because their neighbor was butthurt over their parent's decisions?
Those "simple" solutions may be nearly impossible for a person depending on their situation. Again, few things are black and white.