> I would use barricades, tazers, pepper spray, traps, smoke, fire, light, sound, and other means to dissuade the thief

You have time for all that? Using a tazer or peper spray means your basically in well within pistol range and very close to hand-to-hand range. How exactly are you going to deploy your sound or smoke weapon?

> Guns are mainly useful for offense. Maybe that's why some preppers want them.

Guns are plenty useful for defense. Have you ever received any gun training?