Morality is not an important concept. If you discovered that it were objectively good to rape kids, are you going to suddenly start liking that? Are you going to cooperate with that? You'll probably just choose to be evil instead. So in the end you're always just going to do what you want to do, so why even worry about morality? You only believe in moral systems that support your preconceived notions of right and wrong so why not just cut out the middle man?