The main thing it glorifies I think is that boys will be boys, not drugs per se. Those who criticize them just don't understand that boys have to find their own way, and it ain't always pretty.
Compare it with Snowfall: the main character's family has at least some history of drug dealing and he only succeeds because he discovers a cheap and ultra-addictive recipe for crack cocaine and because the CI-freaking-A is using him to fund the global war on communism. Recurring characters get killed off in dumb gang skirmishes all the time and the drug addict with the most screen time is literally a shell of her former self that can barely get through the day up until the latest season.
Or compare it with The Wire: all the people involved in the drug game are only in it because they have literally nothing else to live for except the glory of the game. Basically no one survives except the cops and Bubbles never really gets fully clean.