The question is "Why did we ever make MJ illegal?".Why do they want to legalise marijuana?
The question is "Why is it still illegal given that the file of the danger of MJ" has been debunked completely, except for minor facts, minor compared to chocolate or aspirin ...
We know the answer: special interest, corporatism, biased competition (paper, steal, medication, alcohol, tobacco), lack of education in logic and statistics, corruption, etc.
To make a plant illegal is the summit of absurdity, except for the criminals, as prohibition makes it possible to sell it to all kids in all streets with no price nor quality control. Huge benefits for them.