You're obviously affected by this personally, and thus biased. You're blatantly ignoring the fact that few teens have a full understanding of how the human brain works, the chemical interactions involved, or the long-term effects that are possible.
Cigarettes were once actually endorsed by doctors, but we all know better now. I'm not saying this is anywhere near that bad, but that's because I'm admittedly not anywhere near an expert on this - I know the limitations of my knowledge, and when to defer to someone with more expertise. I would suggest you find the humility to do the same.