Doing drugs, on its own, is a victimless crime. Doing drugs only hurts the drug user. The user can abuse the drugs then things get bad, that's why more strict penalties would be nice.
Let's look at a slightly different (and somewhat exaggerated) scenario. Say you buy shoes made by a brand, say, Adidiboks. The company that makes these shoes openly admits that they use slave labour to make them. While wearing those shoes isn't a crime, and there's certainly no victim to you wearing those shoes (unless they're like some bright orange shoes I saw a guy wearing today, those have plenty of victims), but you're still supporting the crimes being committed.
This is the type of activity I was alluding to in my first post here -- doing the drugs themselves may be victimless, and if they were legal, everything might be fine -- but by doing them now, you're supporting this trafficking that you're talking about, and likely a lot of the murders/other crimes that go along with it.
