Well, no doubt if more drugs were legal, more Americans would being doing them to get high, just like alcohol.
I fail to see why taking a substance to feel good is so bad for all of the society. For certain individuals, it can be harmful as it masks a deeper set of problems, but is that any reason to throw the guy in prison?
How many people go shooting when they want to relieve stress? That's also a potentially dangerous activity.
(And NO! I'm not stoned right now, I'd saying "dude" a lot more if I was