I don't understand why the traditional interpretation of the story of Noah should be a controlling narrative for how we understand symbols like rainbows.
Because God is a "higher source" than "some artist in the 70's.
This is also why we still have a seven day week.
So God claimed the "Sign"/Symbol first
Gen 9:
"8 Then God spoke to Noah and to his sons with him, saying, 9 “Now behold, I Myself am establishing My covenant with you, and with your descendants after you; 10 and with every living creature that is with you: the birds, the livestock, and every animal of the earth with you; of all that comes out of the ark, every animal of the earth. 11
I establish My covenant with you; and all flesh shall never again be eliminated by the waters of a flood, nor shall there again be a flood to destroy the earth.” 12 God said, “
This is the sign of the covenant which I am making between Me and you and every living creature that is with you, for all future generations; 13
I have set My rainbow in the cloud, and
it shall serve as a sign of a covenant between Me and the earth."
I guess I don't subscribe to your biblical hermeneutics.
Rejecting the Bible is of course an option many atheists take but for those of us who do not , God's Word "means something"
IMO, even ancient people did not understand those "just so" stories in such a manner.
Not according to Hebrew scholars in all world class universities (as noted by James Barr - who was one of them). They see in the Genesis text - a historic record so easy to read that a 12 year old gets the point. Those scholars don't necessarily like what the Bible says or agree with it but they know what exegesis is and they know how the readers would have understood that simple, easy and obvious text.
So easy that it is even embedded in the legal code of Ex 20:11 which is a form of Hebrew writing not prone to myth/fairy tale to make its point.