I thought there was some significant criticism of this series for it's unrealistic portrayal of the period?
It was not meant to be a realistic portrayal. The series explored the historical construct of slavery, created and enforced through law in the American South, through the lens of fiction and using fantastical/surreal elements. It was not a historical but magical realist kind of approach.
I think this is one of the reasons the show didn’t find a big audience—people didn’t understand what it was, or it wasn’t what they were expecting.