I want you to consider instead the possibility that Waterfall came to exist, and continues to exist, for the convenience of managers: people whose methods are inherited from military and civil engineering, and who, more than anything else, need you to promise them something specific, and then deliver exactly what you promised them, when you promised you’d deliver it. There exists many a corner office whose occupant, if forced to choose, will take an absence of surprises over a substantive outcome.
I always have a hard time wrapping my mind around some of the classic user questions: What is this thing for, is it for novices or professionals, etc? I do my best to avoid these questions, because the best thing you can possibly accomplish as the maker of a tool is to build something that gets used in ways you didn’t anticipate. If you’re building a tool that gets used in exactly the ways that you wrote out on paper, you shot very low. You did something literal and obvious.
To become completely lost is perhaps a rather rare experience for most people in the modern city. We are supported by the presence of others and by special way-finding devices: maps, street numbers, route signs, bus placards. But let the mishap of disorientation once occur, and the sense of anxiety and even terror that accompanies it reveals to us how closely it is linked to our sense of balance and well-being. The very word "lost" in our language means much more than simple geographical uncertainty; it carries overtones of utter disaster.