I imagine it's the same with eg hiphop, with the various infamous shady and criminal acts associated with Deathrow in its heydey. Can anyone say if similar things haopen today or that element has died down?
As young metallers we listened to Black Sabbath and Slayer warning us about the horrors of war and the people who take advantage of it. Sepultura telling us about racism and how it completely screws people over. Metallica and Megadeth are as full of philosophy and psychology as any contemporary music, and almost literally warning young generations about various 'monsters' of the world, like commercialism and greed and power. Korn pioneered being open about childhood trauma. Rage Against The Machine (if we may call them on the fringe of metal), well, need no introduction. Nor Devin Townsend. Fear Factory and Porcupine Tree about the relationship between humanity and technology. I could go on all day.
I am really proud of the influence that the metal genre of music has had in forming my personal set of life values.
And this is normal. It's why metal gigs are, by-and-large, chill and safe, and always have been.