This is partly why I ignore moral arguments.
People voluntarily elect for delegative government, delegates are expected to appointed to make best decisions, of course the electorate could be ideologically oppose to the decisions they make. Doesn't make it any less voluntary.
Unanimous consensus is simply impractical, and cost to time and general inefficiency, suffices that sufficient people would agree to a floor on acceptable consensus.
This statement is far from ripping apart any anarchist arguement.
In fact it is actually highlighting some the reasons no government can be based in any kind of morality.
This destroys the idea of any government having any right to rule over people, as it inherently violates the consent of the governed.