This was a well produced and directed series that presents an historical alternative to the currently accepted doctrine. It is far more plausible than ancient aliens arrivng on earth thousands of years ago. Accepted history already documents many things that remain unexplained, such as Gobekli Tepe's age, or even Stonehenge.
While it seems like a long stretch for a surviving single society to have traveled the earth after the great floods, it is not a stretch at all to imagine hundreds, if not thousands of societies world wide that suffered enourmous loss in that cataclysm.
Humanity tends to build near water sources, for obvious reasons. If sea levels went up 400 feet, as described in the histories of the Younger Dryas, then many cultures could have seen their greatest cities and accomplishments destroyed. Being a world wide event, each culture would have that story. Additionally, each culture would have had surviviors that would have tried to teach the lessons of the day.
Everyone trying to claim this is a racist program is actually the problem. Theories aren't racist.