My wife commented to me that one of the unfortunate things about philosophers is that they aren’t mathematicians. When philosophers discover a paradox, they write paper after paper after paper about the paradox, trying to resolve it. When mathematicians discover a paradox, they re-evaluate the model that caused it. Philosophers seem to have a lot of trouble actually evaluating underlying models, though. Instead, they assume some model is correct (in this case, their harm-based moral model) and they criticize the details of conclusions people draw from other models.
I don’t think it ever even occurs to them that their model of “harm” might not be the best one.
UPDATE: Mrs. LotharBot elaborates in the comments.