That is a wildly inaccurate description of historical childrearing. Not only is it cherrypicking examples of horrible advice in order to support its own frankly biased thesis, it's also often incorrect. Obviously, it's nothing short of preposterous to claim that a third of all medieval infants "died from burning cradles". Infant mortality rates (percentage of children that died during their first 12 months) were much, much higher up until the late 1890's in the West, but that was mainly due to infectious disease parents and doctors were unable to prevent until the discovery of the bacteria + viruses that caused the diseases in the 1880's and 1890's, along with changes brought on by better sanitation. Sure, there were lots of ideas we wouldn't agree with today, especially if you go looking for "stupid stuff someone's said in the last 500 years", but there were a lot of good sense too. I'm sure I could compile a list like this just from my Facebook friends' ideas of childrearing, as long as I made sure to take things out of context, pretend a single data point is representative, and point at it and say 'look, they're all stupid!'