No, it's not "my reason". It's an observation - that's all. No causal route was specified.
You already put your words in my mouth; don't compound the mistake by misrepresenting my own words.
Here's an idea: don't "reword it". It's fine the way it is, and communicates precisely what I wanted it to communicate, thanks very much.
One would think the answer is in the question there, seeing as an observation on its own cannot have those attributes.
The difference between this observation and mine is that you are drawing two pan-population generalisations, and I drew none.
I would go as far as to suggest that the idea that any given marijuana smoker can be considered smarter or more morally considerate than any given non-smoker is not sustainable based on any of your personal observations.