that's all well and good but it's always nice to be able to CHOOSE whether or not I'd like to take cocaine (or any drug) or not without the specter of legal recriminations hanging over your head, or the loss of employment due to the invasion of privacy which is drug testing (the most common methods of which have nothing, necessarily, to do with finding out if you are actually impaired while performing your duties). Drug addiction IS a horrible disease; the problem is that most people understand nothing about it, regardless of protestations to the contrary, so the sufferers of said disease are actually victimized more, even now.
ALL drugs should be legal, as should be the choice to take/not take them...y'know, like it'd be in a free society. I don't believe there'd be any more addicts than there are right now. And we've all heard the arguments "for" a hundred times (regulation, tax, education, etc.)
"How do you feel?"
"Like the Kling-Klang King of the Rim-Ram Room!"
And when you do become addicted (and you will) and then need to enter rehab, who will foot the bill? Your insurance, provided by your employer. And who takes a loss because you're off your job for 3 months in rehab? Your employer again. They have every right to know if you have risk factors that are completely avoidable yet you choose to embrace them. From a character standpoint alone I wouldn't want someone who jeopardizes so much for nothing tangible in my employ.