It's the institution, and its functional role in society, that's the structural problem. There are many well-intentioned, conscientious individuals in the police force. It is somewhat similar to the question of the attribution of moral blame for unjust wars. It is almost universally recognized that unjust wars are the fault of the aggressor country's leadership, and not the fault of the soldiers who fight them. Those soldiers tend to be poor, subject to indoctrination, and are often simply trying to dutifully help their country. In the same way that I don't think we should try and prosecute every Russian soldier fighting in Ukraine, or every American soldier to fight in Iraq, as war criminals - except for where they violate jus in bello - I don't think we should charge all police with responsibility for the injustices of the institution for which they work. Going back to where I began, Emma Goldman, one of the things I always found most powerful in the anarchist tradition is their belief in the basic goodness of most ordinary people - even when they are caught up in a fundamentally obscene system. I think I find the phrase ACAB grating for precisely that reason.