I get that, but I strongly disagree with it, especially as such views do very typically punish addiction and abuse. But that's a medical crisis, a life threatening emergency and often it's accompanied with and began by chronic mental and physical pains.
If it's recreational, who really cares? It's not like those tests are that great anyways, and various OTC and prescription drugs are known for causing false positives. Advil, Tylenol, antihistamines and numerous vitamins are potential triggers. I was shocked and stunned the time I tested positive for meth, but then I was informed it was probably the Xanax that made it happen. Even isopropyl and ethanol alcohol those testing things cannot tell the difference between the two so a blood draw requires a different antiseptic to clean the injection site because if the medical alcohol is used the test will show up the same as drinking alcohol (because it tests for the presence of just alcohol). It's within acceptable limits for some, but the weight placed on a negative test is too great for something where can expect at least a two-digit percentage of them being wrong (I think it's 20-30%, but it's been a long time since I've looked that specific number up).
It's not like we haven't always been using drugs in some form (frequently medically or religiously). Teaching responsible use and the warning signs of addiction and abuse and pointing people in the right direction when that happens is tons easier and more achievable and less destructive than trying to stamp out drugs with draconian measures.