Unironically this. The boomers spent their early adulthood surrounded by the counter-culture of the 60s and 70s but never felt included and didn’t really get it. They thought the angst was against the vague spectre of authoritarianism, which to them was simply the Democrats and their Big Government raising taxes, or something. They missed the anticapitalist part. So they thought they understood the revolutionary left as a superficial anarchism, a fight against authority in general, and not a historical fight against capitalist authority in particular. So when they learn that these bands are anticapitalist, they felt betrayed (by their own ignorance).
Big Guberment
Unironically this. The boomers spent their early adulthood surrounded by the counter-culture of the 60s and 70s but never felt included and didn’t really get it. They thought the angst was against the vague spectre of authoritarianism, which to them was simply the Democrats and their Big Government raising taxes, or something. They missed the anticapitalist part. So they thought they understood the revolutionary left as a superficial anarchism, a fight against authority in general, and not a historical fight against capitalist authority in particular. So when they learn that these bands are anticapitalist, they felt betrayed (by their own ignorance).