In very very short terms, the tools have been designed from scratch without primary stakeholders (veterans, their advocates) for 2-3 years and they are just now considering opening up to stakeholder issues on their github. Instead, they focus on VA employees say they need to accomplish their jobs or even VA contractors.
Certain VA employees have publicly stated ownership of the USDS's work on their behalf, it's "their" software and not the public's or Veterans', and it is clearly designed as such.
I could give very specific examples all throughout the USDS VA Digital Service github account but I'll just leave this nugget[0] (which I wrote) from October 2017. They just stated their intention to begin to incorporate stakeholder ideas only a few months ago[1].
What would actually improve Veteran's claims processing starts with what Veterans and their advocates can do - to SAVE government resources doing the same thing or codifying it into complicated software on their end.
[0]https://github.com/department-of-veterans-affairs/caseflow-e...
[1]see very bottom of [0]