First of all in that thread I already addressed the issue you talked about at Re (tilly) 1: Specify, Specify, Specify, and can heartily recommend clemburg's comments at Re: Specify, Specify, Specify.

However I would like to make a short, related note.

Frequently a piece of software will have 3 or more stakeholders. In that case it is both possible and unfortunately likely to run into a situation where no matter what otion you choose, there will be another that most of the stakeholders think is better.

Consider well the following situation. Suppose there are three options, and three stakeholders. Let us call the options A, B, and C. Now suppose that the stakeholders rank the options like this:

1. A, B, then C
2. B, C, then A
3. C, A, then B

Now what will you choose? A? 2/3 of them think that C is better. C? 2/3 of them think that B is better. B? 2/3 of them prefer A!

Good luck getting a consistent picture of what "they" want...