first of all who needs 12 plants for personal use?

Quit Your Bullshit.

I think too many people think they can determine numbers and limits without any clue about growing, personal use, and so on.

Here is a safe-for-work simple DIY hydroponic setup for vegetables or whatever. A slow trickle of water with nutrients constantly flows through the pipes. Using this method, it is possible to grow tiny single-flower cannabis plants. This involves trimming and throwing everything else away, tending to the plant almost like a Bonsai over the course of a few months. Once harvested, the buds should be dried, cured, and even aged.

So how much weed would 12 single-bud plants grown in a setup like the one picture provide? Hardly enough to start a distribution network. I really think you would need to scale up way beyond 12 plants at a time, and this method allows for that.

This method also allows one person to stock up some weed for "a while" depending on his or her rate of personal use. (If stored properly, marijuana can last quite a while.) This method allows one person to cycle between growing weed and veggies or herbs or whatever. That seems appealing if you're going to have some fancy hydroponics system. I live where it is even legal to gift up to an ounce to an adult, so stocking up could also include planning ahead for that.

Thus personal use could easily apply to someone growing a dozen plants, even tall and bushy, with the intent to stock up for a while and save some to gift at the holidays and not have to grow year round in a never ending cycle. I'm not saying that the guy busted for growing was doing this.

But some people think they can count the plants and the jars or vacuum bags of stock and say, "nobody needs this much" because they pull numbers out of the air without having a clue about any of this.