Metal helps us embrace our dark side.
From my post in the Cymatics & Sound Healing section:
Metal music can be extremely therapeutic as it allows us to confront, feel, and purge negative emotions. Of course, everything is best in moderation, but anyone who enjoys heavy music probably gets what I mean.
I can't speak for everyone, but this is my personal experience. It's a catharsis to embrace and purge negative emotions. I can feel heavy with hurt, anger, or sadness, then listen to my favourite bands, and walk away feeling cleansed. I believe this powerful emotional outlet is why metalheads are generally known to be nice people. By accepting, confronting, embracing, and releasing our darker energy we create space to be lighter. Everyone needs some kind of outlet...