I think the notion is absurd, to be honest. Animals in nature are beyond good and evil. Animals in nature lack morality because they lack the cognitive ability to conceive of such a thing. One cannot be evil if one cannot be good; dichotomy. Animals have no ill-intent, but to survive, it is very primal. Similarly they cannot be self-sacrificing either, except when governed purely by instinct.
Human beings are the only species capable of reasoning beyond instinct, and capable of choosing to behave in ways contrary to instinct. We are the only species that can subdue compulsions, and give ourselves, our lives even, for everything from strangers with no genetic tie, to ideologies and principles.
I have asked myself the question, "are you a good person if youve never had an evil impulse?" Most people Ive asked this question to have declared rather surely that, of course, that defines true moral purity, sanctity. But I would beg to differ. A person whose never experienced an evil impulse might act on it if they ever did. Ignorance of evil doesnt constitute good. In my opinion, a truly good person is one who, in spite of all of the temptation to do evil, and all the horrendous thoughts he may have, chooses to do good nonetheless.
Even the Christians agree with this notion. Satan doesnt tempt the faithless; there's no point. Its those on the moral path who must be led astray... they are the ones to tempt the most.
I do not subscribe to the notion that humanity and morality do not have value. I do believe they do. Individuals may earn the privilege to be an exception through their own misdeeds, but speaking in the general case all life has value.
The philosophy you speak of is a very Randian / Marxist mentality, in my opinion. I dont have to be religious (though it may help) to recognize that morality is both real and it is objective/absolute (in the sense that it is not subjective to the individual or culture). Is there a single thing in this universe that is?
Nothing in existence is subjective/relative. There are only varying degrees of knowledge and certainty, but truth is always independent of our scope of understanding. Science, physics... all absolute. Discovery of its laws, though, is a different matter.
I tend to think that religions and cultures and philosophy are simply human experiments in discovery... of moral law. We may never have all the rules right, but our histories have shown evolution of understanding. As truths become revealed we change to suit.
Mathematics is a weird thing, if you think about it. It is completely abstract in nature, and arguably man-made. Yet, it is absolute. Moreover, it is also practical. It applies to our lives. It matters whether or not we ignore it.
I challenge you to offer me anything, tangible or abstract, man-made or natural, that has real impact on real lives, that isnt completely objective/absolute.
Morality is arguably abstract, man-made, but it also has real impact on real lives. Whether society embraces these actions or punishes them means the rise and fall of empires, the progress of society, and the happiness of lives. It seems perfectly real to me, regardless of where it came from.
And I have yet to encounter any notion that is abstract, relevant, and subjective. Why should morality be the sole exception to the rule? That claim must surely be argued in its own right.
Some people would argue that ones choices might change with more knowledge or a different set of experiences or a different awareness of the situation. Though that is true, it is also an appeal to ignorance as a tool unto itself to rationalize a behavior. My counter is always the same: what decision would you have made if you were omniscient?
Clearly omniscience isnt achievable but it is the point that there is only one truth, one moral right, whether or not we were aware of it. Its like a baby who thinks you disappear from existence simply because he cant see you. Have you ever seen the "probability" game of guessing how many jelly beans are in the jar? Where is the probability, do you think? The count isnt variable; its static. So where is the variability that creates the probability distribution? Its to be found in human uncertainty of the count, not in the reality of the count.
Abortion doesnt become moral just because you arent certain in its immorality; if youre aware of the dilemma, of the controversy, then youre choosing to act in liberal ways to commit acts that you know full well may be immoral, and youre consciously and deliberately using moral uncertainty as a means to an end, to achieve a selfishly motivated goal. That alone is pure evil, and it doesnt absolve anyone of guilt. Even if it turns out abortion is moral, the cognitive leap and willful ignorance necessary at the time to justify it surely is immoral.
I hope that at least offers some insights. In summary: Ignorance is not a tool, there is one truth, uncertainty and ignorance arent the same as subjective truth, discovery of truth is a burden of intellect only to be found in sapient species, variation in morality between philosophies doesnt prove morality subjective, it only proves the human endeavor across isolated populations to evolve and discover, and nothing that truly matters in this universe is a subjective notion, no matter how abstract it is.