True, mostly. People do get addicted to sugar and alcohol. Though it appears about 30% of people get addicted to MJ use [1] which makes them moody or restless. Does that really hurt others, more so than someone not getting their coffee in the morning? I get moody without my coffee. The other issues they list appear to only affect the person with the dependency.

I suppose if we go down the rabbit hole, if a person is so moody they lose their job and they have children dependent on them, that's a problem. I would put that in the same category as drinking on the job though.

[1] - https://www.drugabuse.gov/publications/research-reports/mari...