The way you speak is the way you are treated.
Not too long ago, I learned about a program that teaches inner city children “business talk”. That is, learning to speak the lanuguage of the business world, so that as they grow, these children can communicate clearly in the broadest possible community. It is an admirable lesson taught from a place of great concern: that when these children become adults, they will be judged immediately (and perhaps harshly) not based on their skills or talents, but on the way they present themselves, and a large part of that is the way they speak.
That concern may seem clear with children, but it is no less true of adults. Have you watched some of the “reality” shows on TV lately? It seems that cursing, yelling and rudeness are qualities to be celebrated. Clearly being obnoxious gets a lot of folks on television, and many of them go on to more and more fame – obnoxiousness pays off.
So if being rude can make you rich and famous, what is the value of business talk? Why should anyone believe that speaking clearly and courteously is worthwhile? The way you speak is the way you are treated. I have to believe that some of the reason we watch those shows is to feel superior. In the same situations, we would behave better! Or even further, we would not put ourselves in that situation in the first place!
But to the extent that society rewards rudeness, this lesson may be missed. And while someone may temporarily feel superior by outshouting someone else, their insecurities show behind the bluster. A quality presentation is respected more than bullying noise, so consider how you want to be treated before you open your mouth.