“So how did medical mj become a billion dollar industry in CA alone, despite the fact that patients can grow their own?”
Because it is heavily regulated. It isn’t totally legal like tomatoes are.
Even in CO it is heavily regulated, you can’t just till up the backyard and start growing it.
Use common sense, anyone could grow a dozen tomato plants. At best you will have fresh tomatoes for a month or so, then you are done for the year. That is why their is a commercial market, so you can get them all year.
A dozen pot plants would keep you stoned out of your gourd all year. It isn’t used as a fresh product, so storage isn’t a problem.
Correct, and adults in CO and medical mj patients in CA are allowed to grow six plants at a time indoors. As you say, that's plenty to keep them stoned for a year. Yet, enough of them choose to pay at least $300 an ounce to generate $1B in sales.