Kennyr
I can assure you that:
a. You are correct
b. DPA PMs are routinely castigated if they do such a thing
The detail and insight to be had from speaking to users is invaluable, because the devil is in the detail. However, you learn quickly in DPA that you can do the detail, or get promoted. Not both. What is detail? Well, I've been told it includes safety, quality, configuration control, airworthiness, systems integration, anything in the in-service phase, and so on. I've known some excellently initiated projects, which could be delivered effortlessly, to be cancelled or at best diluted by DPA on the grounds that "it includes integration, too risky, ditch it". Things will improve immeasurably for the front line when such people and their attitudes are themselves ditched. The Army, in particular, seem to suffer from this. (e.g. BOWMAN). The attitude does exist in the aircraft world, but there are usually sufficient safeguards (people who will stick their necks out) to ensure one man's drive for promotion does not result in catastrophe. (But not always).