Most left/social/minority/lower-class/marginalized music and bands developed because they come from a lot of oppression and dispossession from authority and powerful wealthy groups that seek to hold them down.

Rap and hip-hop was born out of the black US ghettos from young people who were fed up with the poverty and drugs made worse (and sometimes caused) by government and authority and protected by the police. Rock, metal, alternative, grunge were all born out of young people wanting to break away from the modern straight uptight conservative moralistic world everyone was forced or made to feel to take part in. New wave and pop were born out of young people who just wanted to stand out and be heard and in the 80s used it as a vehicle for political messages (especially about constant danger of nuclear armageddon during the Cold War era)

I’m sure there are angry anxious young men and women from wealthy backgrounds who feel that their freedoms are being taken away … but they will always be completely outnumbered by the millions and billions of poor and near poor people who look at them as the enemy.