He probably cared about his own social grouping (his immediate circle); I, on the other hand, place a very low value on Uncle Joe's life. And that is what it all boils down to -- value is arbitrary and what we assign it. You have not shown that it is objective in any way, shape or form. Hell, you have definite opinions about the worth of some people (you're always bringing up Stalin and Hitler, for instance). I won't ask what value you place upon me ;^)>
Uncle Joe could care less about what you think, he's busy murdering people. And you now have to admit that Uncle Joe was not wrong, and that torturing babies is not wrong - as long as someone in their subjective thinking believes it to be right. If value is what we assign it, then so are morals. You can't observe morals - they are arbitrary personal prefernce in your system. Social grouping and natural selection have nothing to do with right and wrong and you admit as much above. Indeed, cruelty and non-cruelty are equal in the objective sense (Marquis de Sade doesn't care about your opinion - his is of equal value). Just be intellectually honest enough to admit it - you have already said the same thing using different words.