Well, alcohol abuse is a sensitive topic, one the U.S. has been dealing with for a long time (Prohibition, MADD etc).
However, alcohol abuse is one of those problems that can wreck the lives of everyone around the abuser, and some people on this board have had to deal with an alcoholic loved one. Some people, like you and me, can manage alcohol consumption quite well. Many others, who aren't as lucky, try to manage by making jokes about their dependency. It may be that jokes about excessive drinking don't go over quite as well as they did back in the day.