I think most of us can agree that the TV portrayal of drugs (inc. alcohol) is unrealistic. TV writers look into the newspaper and say "Hey, Ecstasy (or speed, or booze, etc) is a big drug these days. Let's write an episode where Carlton (or Chandler, or Urkle, or whatever) does some and ruins his life.
They are playing on people's preconceptions. That is what TV does. 48 hours tells people what they already believe. My mom knows what she knows about drugs from TV. Kinda scary when you think about it