Parents don't want them get high and hormones make them want to rebel. Plus the parents always say not to do drugs because they are bad for you. In the same tone we tell not to eat candy.
Kids like to experiment with things. It's part of curiosity. I personally feel that if a kid wants to know something, they will find out, the only thing parents can do is to warn them of those habits and try their best to prevent it.
It's because nowadays , children are allowed to use the computer and the internet from the age of 5. Of course, it is not normal for a 5 year old to own an iPhone either, but parents have become very irresponsible due to the technological explosion. They believe that if they offer technological luxury to their child, the family will be looked up to, which is not true . The internet is not appropriate to children under 14, with no excuse !