A quick survey of the Oregon Department of Employment shows the majority of jobs offered (above minimum wage) are requiring drug testing
Your sample is about as nonrandom as mine: jobs in a particular region and a particular skill range (Departments of Employment don't list CEO openings). So it remains the case that the market is far from unanimous on the value of drug testing.
Now what about my other question: "Should the voluntary choices of SOME employers be forcibly imposed on ALL?"
Answer: All? No. but in some occupations, ya, I'd like to see it mandatory. You know like airline pilots, truck drivers etc.
Starbucks? Well I'd just leave it up to the employers.
I'm just pointing out that employers find it just not worth it to employ druggies.