Many thefts are committed to get drug money. The majority of traffic-related deaths are drug or alcohol-related. And personal crimes such as child endangering and domestic violence are usually fueled by drugs or alcohol.
Many drug crimes should continue to be dealt with harshly. The people who are harmed by the selfish, destructive acts of drug users and drug dealers deserve nothing less.
Wait, I didn't hear anyone say anything about not punishing thieves, drunk drivers, and child endangerers. I'm pretty sure everyone's in agreement about that. If someone steals, can't you prosecute them for stealing? Am I missing something?
The abundance of crimes with actual victims is all the more reason to stop wasting criminal justice resources on people whose only crime was taking a drug that isn't allowed.