Do these people honestly not consider that their kids are watching them speed, failing to indicate, aggressively tailgating and talking on the phone whilst driving and thinking that this is perfectly perceptible behaviour.
Yes and Yes. The circle of influence on children is large and their local social groups have a far bigger influence than their household. As a kid I was not just in my parent's car. I was in their friend's car, in my friend's car, and in my parent's friend's car. As a 16.5 year old I felt an incredible sense of power when I got my license. I belong on the road, and someone told me I could be on that road so screw everyone. I OWN THE ROAD. That's the other thing about being a teenager, living at home with parents my responsibilities extended to not failing school and cleaning the dishes. I didn't buy the car, I've never had a fine, I was God's gift to the earth and damn was I indestructible.
Now here I am many years later and I wonder how I got away with my recklessness. I didn't learn any of that from my parents who always drove slower and more carefully than my grandma.