Here are a few typical headlines I've seen recently about Colorado's legalization of marijuana:
Washington Post: Since marijuana legalization, highway fatalities in Colorado are at near-historic lows
Vox: Marijuana legalization didn't stop Colorado's decade-long decline in teen pot use
HuffPo: If Legalizing Marijuana Was Supposed To Cause More Crime, It's Not Doing A Very Good Job
There's a phrase missing from all of these: "so far." I hope that pot legalization turns out great and every other state eventually follows the lead of Colorado and Washington. But honestly folks, it's early days yet. Legalization almost certainly has long-term dynamics and feedback effects that we simply won't know about for years. What happens during the first few months is all but meaningless. Even if the stories themselves are more nuanced, this ought to be reflected in the headlines too.