Yes, having pot sold by money-hungry corporate marketers might be better than having it sold by money-hungry illegal entrepreneurs: more reliable product, less violence, fewer people behind bars, some tax revenue.
Or it might be worse, depending on how successful the marketers turned out to be at manufacturing more of the out-of-control users who generate most of the sales of any addictive drug, whether a legal one like alcohol(or legal cannabis, if it arrives) or an illegal one like cocaine (or cannabis today). That 80% of consumption will be by the 20% users who use the most is more or less a fact of nature, independent of legal status. So problem users, not casual, responsible users, will be the focus of all that marketing attention.
But why assume that those are the only choices? Why not use regulation to put a brake on market concentration in the new industry? Or require that cannabis enterprises be organized on not-for-profit basis? Or (if the Federal government would allow it) make cannabis sales a state monopoly, and run it – unlike the state lotteries – in a way that aims to minimize addiction rather than maximizing it?
The choice between Chapo Guzman and Big Marijuana is a false choice. Demand something better!