Same with anything that requires a security clearance. I know a lot of good engineers and they all tell me it's tacitly accepted a few of their coworkers are functioning alcoholics. Because that's the only drug they're legally allowed to do
Canadians are fixing this. They are allowed to smoke pot in Canada. But then they get US clearances to work with US forces (ie NORAD). So the US clearance people are tolerating it. Change has to start somewhere.