Criminalization helps nothing, achieves no positive goals. Quite the opposite. We've been trying this for about a century, we've seen the results. At some point you have to act on the evidence.

We're talking about maybe a slight increase in health issues (legalization does not imply a significant increase in use, eg cannabis usage in the Netherlands is pretty average for Europe), as opposed to the entire monstrosity of the War on Drugs, including the empowerment of violent criminals ranging from local gangs to international cartels.