Not using indicators is an everywhere thing. Here in the land of Ma$$holes the big things are passing at high speed in the right hand lane and tailgating. The newest brain-dead stunt to hit the streets is driving 100+mph during rush hour.
I was bad at right hand passing until I started hypermiling. Now I’M the guy slowing everybody down on the two lane stuff. And it looks odd because I drive a Scion FR-S with Z rated tires.
BTW, I’ve passed on the left shoulder before. Quite a few times in my lifetime, btw.
My father took me to the airport one day a few years ago and I know where I got it. We were in his Ford Ranger on the 405 S curves in Renton and he was so irritated with people poking in the HOV lane that he passed them on the left shoulder. It even freaked me out. Oh, and he was 82 at the time.