Industrial hemp is a completely different thing from marijuana -- although they are the same species, you can't get high from smoking hemp; the THC levels are just too low.

And yes, there are other plants that have some of the usefulness of hemp (bamboo, sisal, flax), but it is by far THE most useful plant for many many different purposes, plus it's a very sustainable crop. It's almost a miracle plant, so it's great to see that it's starting to be allowed again for commercial use in some countries. I have some hemp clothes that I like very much.

As for your stoner friends, I feel your pain but I also think it's a healthy stage for a lot of people to go through to get to know something more about their own inner world. 97% of them will get over it in a year or three, though if they get stuck in it they might benefit from a good kick in the butt (and some therapy to get to the bottom of whatever they're avoiding facing by being permastoned).