Because he liked making stories up to amuse people or to keep them in line?
God told Moses what had happened.
Moses said that God told him. Nobody was there to confirm it.
Hide your face from truth if you wish, that is your perogative.
I sincerely doubt Moses account of the non-evolution aspects of a serpent losing its legs is there ‘to keep people in line’.
So you discount that God is the author, opine that Moses lied. Yet the accounts given in Genesis all have ‘witnesses’. The plagues in Egypt. The Red Sea parting, etc.
What you are doing by attempting to discount Genesis, is to discount the Bible and/or God. In so doing you remove the unalienable rights granted you by your Creator. In so doing, you remove the basic foundation of what made this country great for so long. Good job.