"It's the documentation, stupid."
In my Real World Software Engineering Methodology (RWSEM), developers realise that software specification is an important document. This software documentation is there to protect everyone and to increase the quality of the end software. This software specification should be a document that is binding, useful, and meaningful. It should not be obsolete mid development nor at the support phase. It should be binding during these phases.
I don't know why this is so unpopular. Perhaps the idea is too simple. We need fashion methodologies in the companie's web site and in RFPs, that in practice translate into the well-known terrible Chaos-Waterfall.