[gpderetta]

I have only been doing this for the last 20 years, so maybe I don't know, but it seems to me that requirement gathering is trivially software engineering. How can you implement something if you do not know what you need to implement. Figuring out what it need to be built and how to build it are closely linked. A good project manager will help collecting any missing domain knowledge, but ultimately it is on the architect to make sure that all the right questions have been asked.

And it is given that not all requirements will have been discovered before a development start or that they may change during development.