Coming a bit late to the party, but one aspect of this is that there is already massive usage of cannabis in Germany, and in many areas quite a significant amount is decriminalized.

In recent years, however, crappy cannabis adulterated with synthetic cannaboids have become pervasive--they're inferior to the real stuff, addictive, and deeply connected with organized crime. Legalization will likely result in a safer supply for everyone, while also removing a huge money source for criminals.