So you assume he worked this through from first principles and is thinking critically and has checked his sources... because he works (well, worked) at Google?

So you assume he worked this through from first principles and is thinking critically and has checked his sources... because he works (well, worked) at Google? I can tell you that the norm among engineers, even at Google, is to receive lore and anecdotes from people slightly more educated as if it were gospel, and to repeat it uncritically until someone else more charismatic comes along. This happens so often that someone wrote a book called [The Leprechauns of Software Engineering](https://leanpub.com/leprechauns https://leanpub.com/leprechauns) about the unsourced commmon knowledge that engineers will blindly repeat without thinking about it.