Thanks for sharing, I like that it discusses different states' varying implementation.
Still, I can't help but hear some of the old alarmist cries regarding potency ("omg! Its 10x stronger than when we were kids!").
Though I'll still acknowledge the need for research; clearly its not just "great" for everyone.
I like to make comps to how alcohol is regulated and/or deemed socially acceptable.
From Wikipedia, (my bolding)
"Sale or distribution of grain alcohol higher than 60% ABV is illegal (legal if it is sold by a pharmacy or drug store to a person with a prescription), but
there is no upper limit for other distilled liquors (B&P 23403).
[21][22]
You may serve alcohol if you are at least 21 years of age."
en.wikipedia.org
Not saying "cannabis good!, alcohol bad!", just pointing out some of the uneven treatment of the two in today's culture.