I never understand the point of memes like this

And therefore….?

I’m never sure what people think is the point of saying this. My tendency is to assume that, in a place like the Tigris-Euphrates Valley there will of course arise stories of great floods. What do you expect? And why would anybody in the Bronze Age do anything other than attribute such calamities to the gods or God?

What matters about the Genesis Flood is not that it shares a lot in common with similar stories from the same time and place, but the way in which the inspired writer reworks traditions that are already ancient by the time he writes them down. The flood is a re-creation myth that both takes themes from the story of the Creation and the Fall and retells them:

• world born from watery chaos
• man placed in a Garden where he consumes a fruit that brings a curse redounding to future generations
• promise of redemption and a renewal of covenant

…but also looks forward to the real Main Event of Torah: the story of the Exodus in which Israel will again be born out of water, again enter into covenant with God, and again commit a grave sin with the Golden Calf resulting in Consequences for future progeny.

That inspired writers make use of materials floating around in their culture seems to me as much an indictment of the claim of inspiration as the charge that because humans are made of the dust of the earth, God cannot have created them.