It's interesting to think about what society views as funny, and what it does not. Comedians make lots of jokes about drinking alcohol, but you generally don't see jokes about serious crimes like rape. (In the rare cases where they occur, the comedian is usually scolded.)
Where do drugs fit in? A few days ago I was listening to a comedy show on NPR, when they interviewed the musician George Clinton. He had lots of amusing stories about dropping acid back in the day. At one point he was asked if he had completely stopped using drugs, and did admit to getting a medical marijuana card. When they asked what illness he suffered from, he said he told the doctor that he was a recovering crack smoker. Of course the NPR studio audience was laughing uproariously at all this humor.
So let's think about how our society thinks about drugs, alcohol and rape:
1. Alcohol ruins millions of lives, but drunks are often funny.
2. Drugs ruin millions of lives but druggies are often funny.
3. Rape ruins millions of lives. Not funny.
Now lets think about how our society treats each sin:
1. Alcohol: Legal for adults.
2. Drugs: Thousands imprisoned for drug violations, often for long periods of time.
3. Rape: Thousands imprisoned for rape violations, often for long periods of time.
I suspect our society has a double standard here. Perhaps we think that our middle class kids should not use drugs, but if they do they are not hurting anyone else. It's not like rape. They are only hurting themselves. Prison is not appropriate. And celebrities we love should be encouraged to get rehab, and if they clean up we can even elect them president. But if members of the underclass use drugs or sell drugs, they should be put away, so we don't have to deal with them.
George Clinton is a well-liked musician, so his drug use is humorous. But the guy who sold him these drugs is (apparently) very evil, and must rot in prison. He probably doesn't get the joke.