I see where you're going with this and agree to some extent. Yes, as a "Plant" there is no use to regulate it...do they regulate Roses and dandelions?...NO.

But, if said "Plant" is going to be used for human consumption...It's probably a really good idea to at least have minimum standards on cultivation, processing and packaging to protect the consumer.

Wheat, Barely, Yeast, etc for the use of consumption by humans (i.e. Beer and other alcohols)...are all regulated.