Thoughtful post. I cannot say I agree with what appears to be a relativistic or subjective view of morality.
I believe the most profitable form of morality concerning men (morality or righteousness concerning God is another topic entirely - only in Christ) is what we commonly call the Golden rule found in verse 39 of the following passage:
Matthew 22:37-39 KJVS
Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. [38] This is the first and great commandment. [39] And the second is like unto it, Thou shalt love thy neighbour as thyself.
I believe we know this rule intuitively but often our conscience will tell us when we fail to keep it. I think this is natural due to man's fallen nature (under my philosophical construct). False religion on the other hand will often impose a rigid sense of morality in others but are often hypocrites in doing so. True gospel believers, few and far between as they are, know that the law is fulfilled in love. Self-righteous hypocrites will weaponize the law using it for purposes not intended biblically.
I see a great deal of this, even in philosophical sense, requires a somewhat religious (Christian) approach to the subject, which will not open to those who do not share or know the religious teachings and morality of Christian religion.
For those who do know the teachings or do not, but are not able to feel love and thus act according to the love required, I would not say they are not in the right morality. Even though I can't even see how loving yourself and others would require it to be seen as morally good, as the love can be good even if not seen as a subject of morality.