Interesting point.
There's great value in working to live in better harmony with all creation. But I think there's a tremendous difference between a person who - for example - takes life because it gives them some sort of twisted satisfaction (true psychopathy) and a hungry man who kills a deer to feed himself and his family.
As long as there is hunger and suffering among people on a large scale, pragmatic decisions will be made. Note - I'm not attempting to say this is necessarily right or wrong, only that this is the reality we have to address. If you ask a hungry coastal village to stop eating fish, do you think for a moment that will work? If, on the other hand, you develop tools and technologies to help them feed themselves as effectively and make them available, now you have a viable alternative. None of those hypothetical villagers, by the way, are being cruel or psychotic for eating fish. They are simply trying to survive, which is the first instinct of every living thing.
This is of course true. If I were living a life like those you describe here I would be exactly the same, and it is not psychopathic. But we are discussing the modern, post-industrial age, where some people seem to believe that chicken grows pre-wrapped. This dodges the point. The 'distance' in our age from the consequences of our actions is used to justify choices that would never be made if direct contact with our natural resources was present. This 'distancing' is in itself quite comparable to the 'empathic' distancing of the psychopathic mind, and the consequences are identical. This is not about 'first instincts', it is about ethics, and your point strikes me as unintended sophistry. If you need to exploit sentient life to live, you must do it - there is no choice involved in that basic fact, and so ethics doesn't come into it. The moment you have choices (like in our actual lives here in the developed world), you have ethics, and ethics are driven by empathy. Db