One might just as well ask as to why the RAF stayed with "fighting area attacks" and using close formations with a "weaver" right into the Battle of Britain, that is until punishing loses forced them to follow the Luftwaffe with "pairs" and "finger fours", Frankly, the use of QFE and all the rest of the "Q code" should be a thing of the past, indeed I'm told that the pilot course I was on at FTS was the last one which had to learn the" Q code ". The military establishment is always resistant to change , One only has to read about the reception DH got from the "Blimps" at the top when they proposed the Mosquito, or Sir Frank Whittle received in his early turbine work, the RAF could have beaten the Germans with a jet into service easily had they been of more progressive outlook. This attitude is why the RAF still uses QFE, its nothing to do with any real advantage or disadvantage, if you wish to argue the point we can meet you at Puntzi Mountain, or any of a number of strips surrounded by big rocks, but I will be on QNH!