Bus idiots

Something I don't get is people who talk on their phones on the bus. First, how can you even hear what is being said? How can they hear you? I have never had a phone convo on a bus longer than. "Call me back, I am on the bus and cannot hear you." Second, even assuming some super human ability to have an intelligible phone convo on a bus, why would you be the world's rudest jack ass? Third, why would you want everyone around you to be able to eavesdrop on your conversation? Forth, how can you stand the pressure of everyone judging you?