I've had a CCW since I was 19. My state allows open carry, with a few exceptions like churches and government buildings. I can't begin to tell you how many times open carry has prevented trouble.
I say again, bad manners does not equal "trouble". I'm 48 but remember well many a late night or early morning where a group of us 20-somethings ended up at diner or truckstop (we were military on TDY) winding down a little alchohol and high spirits over coffee and breakfast. Often in some little town in Montana or Wyoming. I suppose we were just as obnoxious to some. I'd go back in a heartbeat!