Im coming from the position of being an historical drug user, but also a business owner, just trying to give you a balanced perspective to support the below statement.
You can draw a line between the legalisation of pot and decreasing productivity in the workforce. Certainly when it comes to manufacturing, construction and logistics.
Any type of hard, soft drug use is negative, I have had sales guys doing blow who think it adds to their game it doesn't, it leaves you vulnerable to strategic situations and thinkers,they will take the deal into deep water past the point of your compromised brain condition and have your agree to something below par, pot users are different in the way that in my experience they are usually more unskilled or repetitive trade labour force types where theres theres not as much strategy just productivity and what i has seen over my years in business that with higher levels of pot use in the population lower levels of productivity.
Im not trying to offend anyone, I've been a user myself.