You're asking a good question about whether there is such a thing as good stigma or bad stigma. I brought up smoking, for example; there was probably a good stigma that pushed people off it. Did it go too far, and now people are afraid to even identify and seek treatment? Perhaps it did.
Honestly, we need to look at balance. We need a balance in society in which people feel that other people shouldn't be punished because they use drugs, as those people need help.