This is a logic that is forced on you, in my opinion, by a limited understanding of self. It is the natural product of dualistic thinking, I am and I am separate from everything else. I am bound (defined) by the past. You have settled for methodologies that are quite satisfactory for a life undisturbed by an all consuming need to answer emotionally troubling existential questions. You are content.
Berift on any sense of a need for self questioning, who you really are, you are content with the sense of self your ego provides. There is no God, no God conscious state, no mystical revelations, all that is just a product of human fears and needs, an escape from the harsh, but in your case quite comfortable, reality. You are the center the judge, the determiner of what is ethical and what is not. It all flows directly out of logical facts, no God, no inalienable rights.
But that is just such a limited way to look at it. Scientists have determined that even monkeys have a sense of fair play. it's not like primates are hard wired to manifest cohesive social traits. Just as humans are hard wired for language, with basic gramatical rules that apply regardless of language, the search for justice and fairness is built right into our genes. We didn't really invent a fucking thing. We aquired our sense of inalienable rights in the process of survival as a social ape.
We were born with instinctual moral capacity onto which the forces of imaginative thinking can be twisted into anything. And this is why, if you want to be moral you have to know who you really are, because who you really are was the potential you as a moral creature were born to express. Morality is unlearning attachment to ego identifications.
Your belief that we create what is moral is dangerous thinking because fear and imagination creates monsterous things. To be moral is to seek truth and to reject everything else. Of course, my opinion, again.