I think the question is less “Why do we think that the objective comparison between these things should be anchored on neuron count?” And more like “How do we even begin to make a subjective value judgement between these things”.
In that case, I would say that when an animal is experiencing pleasure/pain, that probably takes the form of information in the brain. Information content is roughly equivalent to neuron count. All I can really say is that I want less suffering-like information processing in the universe.
I think the question is less “Why do we think that the objective comparison between these things should be anchored on neuron count?” And more like “How do we even begin to make a subjective value judgement between these things”.
In that case, I would say that when an animal is experiencing pleasure/pain, that probably takes the form of information in the brain. Information content is roughly equivalent to neuron count. All I can really say is that I want less suffering-like information processing in the universe.