It means the person you originally replied to was correct to call it a "danger", because while it doesn't preclude the possibility of success as you noted, it does make it less likely for a given individual.

No, it doesn't. It just proves the whole point is meaningless. There are successes and failures in both weed users and non-weed users, so you can't use that as a variable for anything.

Interepting it that way just always casts judgement on the user.

> There are successes and failures in both weed users and non-weed users, so you can't use that as a variable for anything.

That's not how that works. The existence of both successes and failures in weed users does not prevent a comparison of the rates of successes and failures between weed users and non-weed-users.

Making the above comparison and noting that successes per capita are lower in weed users of an otherwise identical demographic doesn't cast judgement on anyone.