Sure, you're right--we do. My assertion is that we ought not to give up on who and what we are, on our core identity. When you've got by varying accounts between a quarter and a half of the population engaged in a behavior it's not something deviant, it's a basic, core, fundamental human behavior. It's not like theft, murder, or rape--outlier acts committed by deviants--it's stuff regular, ordinary people do in the course of their regular, ordinary lives. Making moral codes that prescribe against such fundamentally human behavior is nonsensical. Or rather, life denying.
It's an assumption, and I have clarified it a few times, and I'm happy to clarify it again. I'm drawing heavily on Nietzsche here, also from D H Lawrence, if you want more elaborate explanations of the concept.
But in short all moral codes require an assumption at some point. They've value judgements, and we, as human beings, are the creators of value. Sooner or later we just make it up. The question is, what's a good moral code to make up? There have been varying answers over the history of the human race.
One of those most common assumptions out there is the life-denying assumption. This is the core assumption embedded in the moral codes of most of the world's religions. The idea underlying this assumption is that the real world is a bad place, that should be resisted in favour of a more perfect, ideal after-life of some sort. Major religions from buddhism to christianity are founded on this principle. The Buddhists perceive the real world to be a corrupt illusion, the goal of life being to transcend the corruption of the real world. Christianity perceives the world to be tainted by original sin, a horrible place in need of redemption, full of sin, to be rejected in favour of a better afterlife.
The life denying assumption underlying the world's religions is that who and what we are is a bad thing, to be resisted and opposed through moral codes which deny and suppress fundamental human wants and desires in favour of a more perfect idea.
That's a perfectly valid assumption, as far as they go, but it's not one that I choose. I choose to affirm life. I choose to say that who and what we are is a good thing, that our existence should be celebrated, and that who and what we are is desirable, to be furthered, to be championed. That there is not some more perfect idea--that Platonic notions of a more perfect world are illusory. That this world is real, and that what we are, who we are, how we are made, are good things that should be celebrated.
I take it a bit further than that. I believe in life in the sense that I believe in growth, in adaptation, in the ongoing process of improvement and development that underpin the whole progress of not only human society, but life itself.
In any case, by "life" I mean who and what we are, essentially, and by "life denying" or "life affirming" I mean moral codes which either devalue who and what we are, such as Christian or Buddhist moral codes, or affirm who and what we are, such as mine.
If you want to choose a life denying moral code I don't have any way to debate that, other than by saying that personally, I choose life. Sooner or later we all have to make some assumptions about what we will value.