Here's the problem with most anti-drug arguments.
Thinking that someone should be allowed to use drugs does not equate to approval of taking those drugs or thinking that someone should become an addict.
I do not use cocaine, I would never encourage you to use cocaine, but I don't think anybody ever belongs in prison for using cocaine.
Again, cocaine is no worse than alcohol. Being a regular cocaine user is no worse than being an alcoholic. The only problem is that cocaine is far more expensive so it's going to get you broke quicker than a drinking problem, but that's not the drugs fault since it is an inanimate object and is unable to set its own price