""good" isn't a natural property."
That's where you're fundamentally wrong.
You can't disprove something by defining it it to be non-existent. The term "good" very much describes something real (and natural), otherwise we wouldn't be able to think of it.
Put simply its just the act of fulfilling ourselves, and our purpose. We have a vague notion of good actually is, and are mislead to believe that it doesn't exist (as in your case), for precisely the very reason that we aren't perfect at getting what we need. We get what we want, or what we think we want...which is not necessarily that which is full-filling.
As such, we all have a drive to do what is good, in that we all have a drive to lead full-filing lives. Ethics is the problem of actually leading such lives, not the magical creator of some hypothetical property.
"We run on corrupted hardware: our minds are composed of many modules, and the modules that evolved to make us seem impressive and gather allies are also evolved to subvert the ones holding our conscious beliefs. Even when we believe that we are working on something that may ultimately determine the fate of humanity, our signaling modules may hijack our goals so as to optimize for persuading outsiders that we are working on the goal, instead of optimizing for achieving the goal!"
I'm sorry, while I agree whole-heartedly with this assessment, your article is more of an interesting examination of this principle...than a solution, or even any new assessment. Understand that we are flawed, selfish creatures, is only the first step of many to getting anywhere, one that most of us will never get past.
I've never tried it myself, but to offer a solution to this mess, I think it would be interesting to examine the effect of Radical Honesty upon such problems.
Another way of putting it: when and where, exactly, is privacy justified?