If hemp was legal to use for all the associated petroleum and tree products currently in production many large corporations would take a massive hit. Some might even go out of business. Anyone who thinks pot is illegal due to its effects when smoked is smoking too much of it. Thank W.R. Hearst and other like minded money grubbers for pressuring the government and Hollywood into brainwashing the populace about hemp and its so called evils.
A common argument in hippie circles, but one which is completely ridiculous if you examine it.
(1) If the cultivation of hemp was completely unrestricted in the US, the companies best positioned to take advantage of it are large agribusiness companies like ADM, etc. There exists absolutely no barrier to entry for them, and with their enormous capital resources they would price almost every independent grower out of the market.
Hemp represents an opportunity for large corporations, not a threat.
(2) Hemp oil and fiber products are produced in other countries on a mass scale and they are legal to import into the US. So far, such hemp-growing companies have had no luck in pushing US companies out of the paper, fabric, rope and organic oils business.
(3) Industrial hemp is not very useful for druggies. It is very harsh bud with very little kick.