Re: "Why can't they make the Starliner work now"
Boeing acquired North American as part of the Rockwell sell off in 1996. Boeing acquired NAA, RocketDyne and Rockwell's defense electronics businesses.
So Boeing became the service point for the Space Shuttle :-)
Boeing is a shadow of its former self thanks to the bean-counters who set out to line their pockets, while producing rubbish product. During the Apollo era I don't think propellant valves would get stuck after so few duty cycles.