I have worked for an airline where scary attitudes abounded. One was to load fuel in litres, after asking the refueller for the S.G. Ever tried that? And what success rate did you have? He never knew it. I've always diverted on what the gauges told me, so why not start the flight with what the gauges tell you. Cross check the litres is always a good idea, but it's a bit late after the fueller has disappeared to find that the gauges are less than you wanted.
Another scary attitude was that most destinations were CAT 3, and most alternates of those airfields were CAT 3 also, so why take any extra fuel, even in less than CAT weather?! Ouch.