The Noah story is about wiping out humans interbred with nephilum, you see Noah wasnt sinless or anything like that
he just wasnt from any mixed marriages or fornications if
you prefer. If you care to read the geneology in Luke you will find Noah in there, it was a massive gene pool cleansing. If you care to know what nephilum are they were described as giants or fallen ones.
So you're saying God is a eugenicist. So those Southern preachers were right and miscegenation is a sin...