The main point to me is we still insist on this being engineering as opposed to creative writing.
No-one sets out the specifications for a novel, or even a marketing report.
No-one sets out the specifications for a novel, or even a marketing report.
Whatever you're making, there's going to be some set of things that it must accomplish. It's much easier to make the correct thing if you know what those are in advance. The fact that acquiring specifications is hard, or that users don't actually know what they want doesn't change the fact that you want as precise a spec as you can get.
I do generally prefer very precise specs for engineering projects, of course.