You simply haven't a clue what you're talking about -- mostly as a result of juvenile arrogance and contempt for the subject matter. Yours is an ignorance both woeful and willful ...
The
tree of the knowledge of good and bad employs a merism, one found only one other place in the Torah. It refers, as Sarna notes, to
"the capacity to make independent judgments concerning human welfare." To equate this with [always] knowing right from wrong is preposterously stupid.
I am blessed with a fair number of grandchildren who have yet to reach the age of responsibility, yet each one knows that it is wrong to hit their sibling, wrong to ignore/disobey their parents, and right to hug their grandfather.
You try so hard to denigrate the Tanach and those who formed it, and manage only to expose your own shallow pettiness. Too bad ...