I think this all comes down to a person's ability to control their intake of anything, including Marijuana as well as controlling their ability to function well at work. For someone to be addicted to something; it's common that they make the connection of marijuana use with recreation. So, they tend to be in a relaxed environment. Of course, Marijuana isn't an upper either. So, all of that makes sense. That minds are changing isn't a new thing. They're being forced to change under the loosening of strict laws in a few states. Also, they can't fight the fact that it's bringing in tons of revenue for them so, anything against it tends to get thrown out the window. But what are employers up against at this point? Are they going to establish some new laws against marijuana use? No doubt they already have. But more of them know that their employees are likely to be using it and will loosen up their restrictions against it as well. So the line of what makes a person an addict verses normal use has moved and with this, work ethics will evolve too.