Rather than address specific questions, let me offer two analogies. Forgive me if I tell you more than you already know, as, who knows, others might actually be reading these posts.

I liken morality to the spots placed on the bowler's end of a bowling alley to aid bowlers in aiming their rolls. It turns out that humans just don't have the hand-eye coordination to put a ball where it needs to be by aiming at that place. We are much better at putting the ball on a certain spot on the alley and rolling it in a certain manner in the direction of a nearby spot also marked on the alley. Golfers make a similar choice: they control distance (grossly) by applying the same swing to different clubs, rather than trying to apply different swings to the same club.

These choices are technological adaptations to natural talents, and the talents are adaptations to our ability to create technological adaptations. An equilibrium arises between the "cost" Nature expends in creating talents and the costs we can save Nature by being creative. But the spots on the alley and the differing club-lofts are workarounds, ways of getting where we want to go because, given our talents, we stand a better chance of getting there by using them than not.

Neither the bowling spots nor the club lofts "just happen." Serious thought goes into designing them so that they give maximum benefit to those using them. People earn their living solving the problems these technologies address.

The second analogy is to Plato's cave. I have to assume that in the cave, where the people can only see shadows, there are guys whose job it is it help people make sense of the shadows. I imagine that the guys doing this work would get pretty good at it, but that they might differ as to how to interpret certain shadows. Dare I call these guys "philosophers"? (Yes, I do.)

I see the (moral/ethical) philosopher's job as helping us make sense of the insufficient information we have about the consequences of choices. Should we strive to become good people and trust that our decisions will be as good as they can be, or should we agree on and learn some rules? Both approaches are useful only because we have imperfect information. If we had perfect information (whatever that means), we could use game theory. But we can't have perfect information. So we hire philosophers to paint some spots on the bowling alley of life.

Philosophy is a very worthy, indeed, essential exercise, and only humans can do it. But that's the bargain Nature has struck with us. We have brains, and because we have brains, we are "expected" to create tools.

In the context of your note, I agree that we can't "explain" what people are doing using game theory, but that's because the rules of the game are not accessible to us. So we do philosophy. As we should. I think our disagreement is in that I think the only relevant difference between man and beast is that man can make better tools. In the sense that quantity has a quality all its own, we can certainly say that humans are "different" from animals in a way that is different from the way dogs are different from cats or even from trees. But, in my view, metaphysics is something that the unique difference between us and the animals enables us to invent, not vice versa.

I don't understand the question about genetic fallacy. The libertarians are not wrong because I think they are fools; I think they are fools because I think they are wrong.