Augh! Stop reading my mind! I've been working to push DDD-ness on my company for a couple years now, and it's been tough.
A contributing factor is organizational: There can be a managerial or "coordinator" layer composed of people who have neither the domain-knowledge of end-users nor the technical-knowledge of programmers.
Unless this layer is composed of very good people, what you get are specs that resemble a game of "telephone": Even if they're detailed with mockups etc, what the specs actually encode is what Alice thinks she needs to ask for in order to satisfy the request of Bob which is based on him thinking about what design might solve his problem, etc.