But then I prefer safety to convenience. Once we do something marginal we get used to it and sooner or later it becomes 'standard practice.' Just personally I think adjusted power take offs for noise reduction and 'saving the engines' are madness and the idea that we should fly an aircraft with three hundred passengers on it five thousand miles with a major systems failure, (and a quarter of your engine power lost is a major failure,) as an alternative to a safe landing that is immediately available is madness too. Just because the aviation community has got used to the idea doesn't make it sensible.
What a load of tosh!! You assume there is no risk assessment! The crew would have looked at all the options! They would have reviewed their situation and made contingency plans for the remainder of the flight. Hence their eventual diversion!
Normal operations on a well run four engine aeroplane!