Sure they are. And the society they created is different.
Is there a stigma to being pregnant and unmarried? There used to be.
Is there a stigma to abusing drugs? This behavior used to be kept secret.
In today's society, not only is there no stigma (hell, it might even be considered a hate crime), but WE support that behavior with social programs. Subsidize a behavior, get more of it.
Now, could it be that "Drugs actually were much less commonly used/misused back when they were totally legal", not because they were legal, but because they weren't socially acceptable or supported by the taxpayer?
First, get rid of the nanny state. Then, and only then, should we debate the legalization of drugs.