It is illegal because the lobbyists for the industries that it would compete with keep paying their bribes(campaign contributions), and our law makers return the favor with legislation that hurts anyone/thing that will threaten their source of revenue. I don't think we will ever get an honest debate about legalizing pot until all campaign contributions are required to be made on an anonymous basis.
Yep, hemp products are legal in the USA, e.g. hemp cloths, paper, food products (like hemp granola), and even hemp shampoo and skin cream. My wife buys the skin care products. The raw material (Hemp) is illegal in the USA so other countries where it is legal make the stuff and import it into the USA. They say there are over 5000 uses for hemp, the fibers, and seeds including making fiber board to build houses.
Look at all the farm and industry jobs we could have if the government would admit that hemp IS NOT the same as cannabis because you would need to smoke POUNDS of it before you would ever get an effect. It is so low in THC that it isn't even worth trying to do an extraction because it would take tons to get even a small amount of worthless hash.
Not to mention the nutrition of the seeds for food. Only the soy bean has higher protein.