[tsotha]

I agree with this. You might be able to grow your own stuff with mediocre success, but most people will be a) too lazy to put in the effort and b) interested in higher quality and more variety than the backyard plot (or closet) is likely to produce.

You can grow your own tomatoes, too, but most people don't, and even those that do usually recover from the gardening bug after two or three seasons.

Also, I expect commercial growers will start using GMO and hybrids. You may in fact be unable to grow your favorite variety of pot because you can't get ahold of viable seeds for the strain you want.