Hemp has a bad reputation because of the cotton industry. You see, hemp is an extremely useful product, you can make fabric, just like cotton, oils, lotions, the list goes on and on. The cotton industry knew this, and hemp was a very real threat to their businesses. As everyone knows, you cant get stoned on cotton. The cotton industry lobbyists did a lot of work in Washington, D.C. to have laws passed making marijuana illegal. Hell, all they had to do was portray hemp and the most dangerous drug in the world (much worse than the nice drug, alcohol) and Congress would do the rest. As hemp/marijuana/pot was declared illegal, the cotton industry had won its battle. There was no more threat to their business from pot and they have prospered ever since.