Agreed, I say wattage indoor, and square footage outdoor would make much more sense.
Why do we need any sort of regulation on this plant? (aside from random testing of people selling it for commercial purposes to ensure there is no pesticides, fungicides, mold, etc)
It's nothing like a speed limit that has a direct effect on others well being.
If someone gets busted using things they shouldnt that end up in the finished product, they need to be dealt with. However there is no good logical or moral reason to regulate the plant by wattage, numbers or sq ft.