When I was still in training, I had the pleasure of participating on a software project to build a "web shop" for internal use at a large IT company. It was a pleasure insofar I was only a trainee and did not have to deal with the politics and all that. One day, a week before the first part of the web shop was scheduled to go live, the programmer I was working for came back from a meeting. Usually, he was pretty laid back person, very friendly and pleasure to work with/for. But when he came back from that meeting, he was
mad, like, "Hulk SMASH" mad.
I asked him, as delicately as I could, what had happened.
This project we were working on, he told me, had been going on for about half a year, and during that time there had been a meeting every week, where everybody involved in the project had an opportunity to get together and review and discuss the progress of the project.
So there was this guy, who had only attended the very first of these meetings, without saying a single word. And the week before the thing is supposed to go live, he shows up again, with a long list of changes he wants to make to the application.
Needless to say, that programmer, and several other people in the room, told that guy how he had six freaking months to tell the programmers about his requirements, and the he could not possibly expect them to make all these changes a week before the application went live.
So that guy goes to the highest-ranking manager involved with the project, manages to pull some political strings, so that manager goes to this programmer's boss, that boss goes to the programmer and tells him, "I know how much it sucks, but you have to do this. I share your pain, but I, too, am powerless to refuse this request."
When building material things, it seems, houses or ships or airplanes or railraods or whatever, people do realize that you cannot tell, e.g. the construction company that you actually want a house with a circular outline rather than the rectangular one the company has been building for the last, what?, three months. Managers at car companies, I guess, do not storm into the engineers' offices a week before production of a new car starts to tell them the vehicle not only needs to be small and fuel efficient, but also needs to be able to work in antarctic climate and run on carbon dioxide instead of gasoline.
With other products - at least, that is the impression I get - people have an intuitive or explicit understanding of the limitations of the things they want to have built, and they also seem to basically understand that you cannot make drastic changes at the last minute. With software, which does exist in the tangible way that, say, a car our house does, people seem to have a much harder time understanding those limitations. I am not sure this is the entire problem with software development, but it is a big part.