Yeah, it was decriminalized... but that wasn't my point. The point is, police didn't care, and it wasn't interesting for young people because of that.
Real problem they had was heroin. So they made heroin(or some replacement) free, pushing out drug dealers from the market. Importantly: providing other help to addicts, so they could/would be part of society.
https://youtu.be/6OYLoPvLzPo?feature=shared (1h video comparing situation in US, Portugal, Netherlands; Netherlands part starts around 27:00)