Smoking is generally considered bad for you. Thus, smoking is portrayed by the villain, so as to drive home the Anvilicious Aesop that Drugs Are Bad. It is almost never portrayed as 'cool' in today's media, and even the Badass seems to be quitting the habit. In children's cartoons, it's perfectly acceptable for a villain to smoke, especially if they blow it in somebody's face, but the hero thinks it's a disgusting habit, or they may be trying to quit. Alternatively, a heavy smoker may be shown as extremely affected by the smoke to show how bad it is. Contrast Smoking Is Cool, and No Smoking.