There's a lot more to it than the economics, though I agree that
alone is an argument against it. I cannot, off the top of my head,
name an abusable chemical substance that doesn't have some other
valuable use: Cocaine is indispensible in eye surgery, opiates are
the most effective treatment for intractable pain, alcohol is a
good antiseptic and fuel, hemp is a strong fiber, amphetamines can
treat many psychological disorders, even Nicotine has shown some
promise of medical use.
Destroy the plants, and you destroy not only their evil uses, but
their good ones, and the good uses of any other plant that might
evolve from or be bred from it.
That some uses of a resource destroy people's live is undeniable
and unfortunate, but the resource itself is the wrong place to put
the blame.
-- Lee Daniel Crocker <lee@piclab.com> <http://www.piclab.com/lcrocker.html> "All inventions or works of authorship original to me, herein and past, are placed irrevocably in the public domain, and may be used or modified for any purpose, without permission, attribution, or notification."--LDC