The problem with the message is two-fold.
Firstly, there is nothing new in children drinking alcohol. Ever since it was invented, some children have taken alcohol to excess. Victorian society was riddled with it, as was Georgian society.
When children worked in factories, up chimneys, on farms, they considered themselves adults, and took their habits accordingly. The modern age is no different, except that children assume their adulthood from the media, and not from the hard school of knocks, as was previously the case.
Secondly, it isn't helpful to link alcohol and heroin. They're different devils.
I don't see this as a statement of modern society. It was ever thus.