Phones are also just a PITA in this scenario, having to dial a number and wait for a reply. They can't be used when wearing thick winter gloves either. Seems as though those people who have walkie talkies and don't use them, simply haven't got used to using them. At first, we always used to forget to take them out, or to charge them. Now I make a point of keeping them charged and, as soon as we get to a lock flight, out they come. They aren't necessary but they do make things easier and far more civilised.