Most of what is built, fielded and maintained by the DoD, specifically the people on the front line of development all the way back to the program offices, is for the benefit of someone/something else, rather, for the betterment of the DoD’s weapon and business system(s) arsenal - whatever form, or function that entails. What is created is for someone else, likely unrelated to a bottom line — Return on Investment scenario and often serving a critical function necessary for completion of X mission or Y task.
So why is there so much clear and shielded 'space' between the two?
Why aren't developers in soldiers/sailors/airman and Marines knickers day in and day out pursuing a better understanding of how their products interact in their space? The DoD’s massive bureaucracy has allowed artificial barriers to seep into day-to-day development operations. It is often the case that a software or hardware product development team will never engage or interact with the folks using their product — :-(
The best product developers in any marketplace deeply understand their customers, or are actively pursuing a deeper understanding of how their customers interact with their product(s). Nowadays this is merely common sense in the hyper competitive tech market. Obviously, the DoD is different, it operates under different conditions and support a different type of stakeholder; however, the better you understand the user(s), the easier it will be to exceed their expectations!
Think about it like this: Have you ever received a gift from someone else that surpassed your expectations so much that you felt like they understood you completely? The idea of understanding the customer so deeply, that you know what they want — when they want it, and understanding their needs more than they understand them is truly difficult to accomplish, with a degree of sincerity very few achieve. If anyone could do it — they would and there would be no real emotionally connected competitive edge.
Take a moment to think about the various products and services in your own life that have reached the apex of customer satisfaction... Are there many? Personally, I can only think of a few (e.g. my first iPhone).
In order to get into your customers heads you have to understand how they interact with your product - almost on a cellular level! You have to: interview and talk with them - not their sponsor or other various barriers; watch them; and have them document their wants/needs; interview and talk with other people who are key to the function of the product.