Not everyone needs to be drug tested. Doctors should be tested three times a week on three different days. Same with law enforcement, pilots and anyone else who holds the power of life and death in their hands.
The roofer, the brick mason, the helpdesk guy, Who cares? I don't even care if my banker is stoned as long as I get my money and not a dime less. Whatever helps ya get through life and doesn't harm others is ok by me.