"That does not stop many people from basing their morality on such a book to such a degree that they find harming others who disagree to be moral. That I would tend to agree with your assessment of morality does not make it any less subjective."
Whether or not those who base their morality on factual errors are impeded by using well being as a standard does not remove the standard's objectivity. Also, you tend to agree with me, because I can provide facts for why considering the well being of those toward whom i behave, or towards whom I use morality, is not arbitrary, in fact, necessary.