Moral disapproval trumps facts.
But even the results of the mom-only surveys seem to show that Americans believe the only decent way to raise a child is with a full-time mother never taking her eyes off her kids. Only June Cleaver types get a pass.
Anyone else—impoverished moms, single moms, moms with big families—are seen as putting their kids in danger simply because they cannot directly supervise every kid every second.