It’s just a general pattern of rudeness, caused by the urge to incessantly spout wisdom. I can’t stand it when people walk n abreast in hallway/sidewalk designed for n people.
If walking and talking on a phone is stupid, even worse are people appearing to be talking to themselves with a Bluetooth earpiece. I’ve pointed out to people at work that if I seem to be talking to myself - I really AM talking to myself!
You can't tell the crazies from the Bluetooth users, especially, if they have long hair.