> I don’t recall Google ever having a rationale for how “don't be evil” helped them make money, either explicitly or implicitly.
Google's success depends entirely on user trust. If users aren't comfortable having Google accounts, having Google host their email, typing their deepest desires into the search box, taking private photos on their Android phone and uploading them to Google's cloud, then there is no Google.
"Don't be evil" is about being a good enough company that users trust you.