Education, not fear is what allows people to decide for themselves if they want to try/use something and it seems more likely that if/when they try these substances they'll at least be prepared for the consequences and be more likely to be responsible with their use.
Anecdotally I have many friends who were taught abstinence. Once they got into weed they realized just how much of a lie abstinence teaching was, they then graduated to trying other drugs, but not responsibly, because they had no idea how these other drugs worked. They had no idea what an OD might look like or what the risk of getting poor quality drugs might do. e.g. look at cocaine - how many people have any clue what that is cut with? I'd imagine almost every single one of my friends couldn't tell you what north american cocaine is predominantly cut with and they couldn't tell you what to do in the event of an OD, or what the exact symptoms of a cocaine OD even are! The lack of education is terrifying, really.