Leaving aside the drug issues here are just some of the uses of processed hemp, which by the way, does not get you high once processed. Also the type of hemp grown for fiber is grown for size, not thc content.
Hemp seed oil (industrial lubricant, lantern oil, plastic base, cosmetic product, biodiesel)
hemp fiber (rope, string, clothing [very sturdy], and fiberboard, construction products [ when properly processed it can be used to make a type of plywood and artificial lumber].
hemp root (soil binder for erosion control)
Hemp leaf (dye for clothing, a medium greem and a pale greenish yellow, CO2 reduction, oxygen generation)
left overs from producing above products (animal feed and biomass for soil construction and power generation)
interesting plant