Drug tests for work !

Le
Okay , so . I work on a large construction site .  Drug tests are required for hire . And if any incidents (or you go home sick) you do a drug and alcohol test . 
It DRIVES me crazy . I feel like you should only be able to be held accountable for while you are at work . I watched my little town of 7000 people go from a stoner town , to a coke/crack head town because coke is out of your system in days . And I'm allowed to go out get shit faced . Wake up hung the fuck over and come to work feeling like poo. But I cannot go home . Smoke a draw , eat my then DELICIOUS supper , laugh at my usually not this funny boyfriend and hop in my bed that now feels like a cloud and sleep peacefully and wake up fresh for work . 
 Just want opinions . You have mine .