Molasses acts as an anti-fungal agent in the root layers which is good for marijuana since most growers over feed and over water their marijuana plants in order to over produce the smokeable buds.
Actually molasses feeds the beneficial biologicals which than can process nutrients directly for plant uptake.
As for the statement "most growers over feed and over water their marijuana plants in order to over produce the smokeable buds"
Thats a pretty broad statement, alluding to the fact that you know the personal grow habits of "most" growers. Considering there are tens of thousands of legal growers in the state of california, i find this statement inaccurate. Overfeeding and overwatering does not overproduce buds. It only makes for a waterlogged, nutrient burned plant.
There is quite a bit of valuable information that can be obtained from these medical growers, especially for those wishing to maximize yeild in smaller spaces.