[quasit1]

I agree, I have worked at 3 different places that implemented demo-driven development. It always looks good the first couple of weeks or even months, but then it goes down hill, just as you describe.

So much important work is not really possible to demo in a way that most people understand or see the gain it gives either.

I think, from previous experience, that demo-driven development sort of works if you are a company or project in the start up phase, because there are a lot of stuff to demo and the development goup(s) can get quite a boost from the excitement it generates.