Often it's not a specific agency or policy that's being protested. They're involved, sure, but the protest is about the brokenness of the social contract more

Often it's not a specific agency or policy that's being protested. They're involved, sure, but the protest is about the brokenness of the social contract more generally--which means that working towards fixing it is everybody's problem. A targeted strike on a police station wouldn't do much to engage anybody who is neither police nor protestor. There are obviously better ways to drive change than destroying whatever's around you, but much like you'd protest a too-low speed limit by speeding, it's not insane to protest a broken social contract than violating it at scale.