Denver decriminalizes magic mushrooms, why does it matter?

Citizens of Denver voted for Initiative 301 which makes the possession, use and cultivation of psilocybin mushrooms among people aged 21 and over the lowest priority crime for law enforcement in the city. What it practically means is that it prohibits Denver from spending any resources to prosecute people with them. Rolling Stone analyzes symbolism of it saying it is "already fueling similar efforts in other cities and states".