An organization staffed by competent people that reports to people that are neither competent in the relevant domain nor willing to defer to those that are remains, as an organization, incompetent. As USDS and 18F are both in the executive branch entities, their organizational competence is limited by the leadership of executive branch; this is particularly true of USDS, which is in the Executive Office of the President.
Instead of having a department make software, they are supported from a vastly superior group of developers that work temporarily with that department.
Maybe its too much to ask, but shouldnt the company providing the software also employ the talent that is used to make the software?
At least part of the original idea for those entities was to serve as a cadre to improve competence government wide.
Having some experience with why government lacks organizational development competence (TLDR; short-sighted management with the wrong goals), I don't think they can do that—they literally are addressing the wrong problem—but the idea wasn't to be a silo of technical skill.