Your chosen method—refuting a rule with a counterexample—throws out all moral rules, since every moral theory has counterexamples.
This sounds a lot like “every hypothesis can be eventually falsified with evidence, therefore, trying to falsify hypotheses rules out every hypothesis. So we shouldn’t try to falsify hypotheses.”
But we are Bayesians, are we not? If we are, we should update away from ethical principles when novel counterexamples are brought to our attention, with the magnitude of the update proportional to the unpleasantness of the counterexample.
The books thing is a real problem. There’s probably a lot of potential impact in translating the Sequences into YouTube video-essays.