The beer industry is a good example. It's nowhere near as powerful or nefarious as Big Tobacco, and in fact the phrase "Big Beer" doesn't doesn't even exist. Beer companies tend to be fairly benign, while the tobacco industry is famous for stunts like marketing cigarettes to kids and trying to suppress anything that suggests their products are harmful or addictive.
So if the marijuana industry turns out like the beer industry, that will be a pretty good outcome, really.
Any public health measures are rigorously campaigned against.
The all-party parliamentary beer group receives funding from the alcohol trade. http://www.publications.parliament.uk/pa/cm/cmallparty/regis...
(What's the largest uk appg?)
[0]: http://www.ab-inbev.com/go/brands/brand_portfolio/local_bran...
I guess my point is, practically speaking, I see 99% of people still buying it even if it's totally legalized and not taboo.
Outdoor requires less moving parts. Still a lot of variables, especially considering you can drive to the store and have your pick ;)
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.
On the other hand, pot can be grown in a computer case or a closet. It's been bred for almost 100 years (maybe more) to be grown out of sight and out of mind. Given a very small amount of research and learning, almost anyone on the face of this planet can grow a marijuana plant. It's called "weed" for a reason.
edit: In other words, it's not exactly the same thing as what big tobacco was doing, which is marketing products on a mass scale, all the while knowing the kind of health damage that such products caused. That is what people had problems with.