DTC, Some Speculation for Your Questions
Yes, when marijuana is legalized, the methods of purchase will most certainly change and as medical/recreational legalization has already done so. I used to grow and have plenty of off market sources for flowers but I still go to dispensaries here in LA. The main reason I frequent the shops is to get candies, edibles, concentrates and other non-flower products. The majority of "street dealers" sell crap. They don't know the strain, the type (indica/sativa), the grower. And it is still illegal to buy black market weed, so why risk the potential legal consequences when the same thing can be accomplished legally. Of course the black market still exists in Colorado but again, that's an even more idiotic risk.
As to your question about "these companies" profiting from rescheduling....AB-SO-F*$KING-LUTELT! Right now the Controlled Substance Act makes it a crime to profit from drug related activity. Therefore, many of these companies are keeping THC revenues at arms length or avoiding them entirely in an effort to remain compliant. I just wrote a paragraph about my past involvement in the cannabis trade back in NY and another anecdote about a friend who grows medical cannabis in NorCal but thought better of disclosing so much information. Regardless, the point I wanted to make was the income from growing is truly astounding. From 60 plants on a 3 month cycle, I was making about $15k/month after payouts. My NorCal friend is doing about $700k profit/year and the operation is expanding.
Now imagine what happens when the ERBB and USEI sets up a commercial growop in Denver. That's large scale commercial growing. And they are opening a dispensary as well so they have vertically integrated the business from seed to sale.
Of course, people will still buy from dealers just like how some people still get bootlegged liquor but that will not be the norm. The average Joe doesn't need to find a dealer or maintain a relationship or risk legal action to get marijuana.
I wouldn't say you are off base. You clearly are market savvy and have a strong financial acumen but I think you may not have a complete grasp on the existing and past cannabis industry. The annual black market for cannabis is estimated between $20-100b. Sure that's a huge swing but it's hard to pin down numbers considering black market players don't report earnings. But one telling stat is this;
For the past decade, despite being illegal, California's number one cash crop has been marijuana, dwarfing the citrus, vegetable and all other markets.
People will get their cannabis from Walmart, dispensaries, dealers and grow their own. The market is just that big. But I have no doubt a handful of companies will make enormous amounts of money from cannabis.
"Emancipate youself from mental slavery, none but ourselves can free our mind"
-Bob Marley