The letter has good intent, although I disagree with him.
From my perspective, I've known countless amounts of people growing up who smoked weed, and I can honestly say over 85% of these kids were not hugely creative, academically superior, and/or really that motivated to participate in an academic structure. I personally wouldn't want my children smoking week, doing pills, or drinking alcohol at all. If after they're on their own, and providing for themselves, and if they chose to partake in drinking and smoking than that's there thing.
Obviously weed has different effects on different people, but I feel comfortable with the way our society handles it and at least not reward people as hero's when doing it, by leaving them on the cover of major brand cereal boxes. I mean do u think this kid who’s now a champion was smoking pot as a 13 or 14 year old in school that idolized a champion who smoked pot himself. I honestly doubt it. Of course, it doesn’t mean that it can’t happen but again in my opinion the odds are against it.
Everyone's entitled to their own opinion, and I think children’s minds should be allowed to develop and mature completely without the cloud of any type of these substances, obviously the challenge is trying to parent a child so that they know when and when not to make these decisions for themselves.