Well, the point was that moral imperatives don't materialize out of nowhere. The question of why humans feel this way is a scientific one, not a moral one. So you can evaluate it, and its effects, in the context of whatever broader goal you're trying to achieve, be it a space-faring civilization, a happy civilization, or even just a surviving one. Most moral imperatives are cached thoughts, subordinate to larger imperatives. Most people can probably be convinced to kill, for example, if they think it's justified.