The fact that you can’t understand the argument that alcohol and drug abuse can have serious impact on children means that you have serious blind spots in your life.
> Haven’t seen anyone advocating to curb marijuana here yet.
You don't think a drug that's illegal in large parts of the world and for which legalization is a highly controversial topic is curbed?
Also, the parent comment clearly took children as an example of people who's live can be drastically worsened by someone else consuming alcohol. Drivers and and passerbys endangered by drunk drivers would be another good example.