If we were talking about cars, motorcycles, or lawnmowers, would you be making the same argument?

I don't understand your question. If someone said "a crash helmet is a common sense safety accessory when driving your car" then yes, I would because it's not a "common sense" safety accessory in that case. The reverse is true if talking about a motorcycle.

Why should I be legally obligated to "disturb the peace" for a mile around when using my range?

I don't know, this isn't my argument. My argument is that calling a suppressor a common sense safety accessory is a bit of a stretch.

Or am I supposed to get all my neighbors within a mile to wear ear plugs?

Why a mile? Safe distance for hearing around gunfire is generally considered to be ~100 feet away or more. If your neighbors are closer than that then, yes, they should weathering protection.