How do you know they are thoroughly waterfall? How do you know they don’t use agile, time-boxing, etc.? Apple is so secretive, it feels like we know of little other than what they are confident about releasing. The things that weren’t done on a schedule compatible with a hardware release, how often are they simply postponed? And for those postponements that they do admit, how many are waved away with a creative explanation? I think you need a good deal more information to back up your point about Apple’s work management.