I have stated elsewhere that the notion of musicians as 'role models' is a nonsense dreamed up by rightwing media gitators.
Of course we want our pop stars to live on the edge, be exiting, be tortoured, be in pain - because most of their fans are, to a greater or lesser degree.
Anyone who imagines that someone would start ingesting heroin because Amy Winehouse does it (allegedly) knows nothing about the appeal of pop, or the psychology of drug-taking.
Both sets of parents should reverse their own dignity bypasses and mind their own business - their children are aduots, and can, and will, do as they wish, regardless of their high-profile bleating.
I would no more boycott an artist for their lifestyle than I would stop driving my car becuase of 'global warming', for the same reeason - it is not relavent.