You know, I'd feel a whole lot more sympathy for Boeing if we, the taxpayers, had not paid nearly twice as much for the Starliner as for the Dragon, and then waited nearly seven years longer than was expected, and can't even expect one clean launch at this late date.
There is no reason to risk the astronaut's lives for what is a small upside P.R. return trip to Earth. Contrast that to something else going wrong on the way home and these astronauts perish. There will be knives out for Boeing and the NASA admin types that made the poor choice to send them home on that helium-leaking, valve-sticking jalopy when there is a perfectly functional Dragon parked in the next bay over, on the ISS.
Between hidden crap software that caused two 737 crashes, the blown out 737 window, the better part of a decade's delay on Starliner, only to discover flammable tape on the wiring and parachute shredding, bad valves, etc. etc., it really might well be time to thank Boeing for their accountant-approved, Wall-Street-grade spacecraft.
NASA: Staunch the bleeding. Replace Starliner.
Now if only there were an alternative waiting in the wings... oh wait! There's Sierra Nevada's Dream Chaser.
Is it not ironic that at the time the contract was awarded, it was considered a bold and risky move to select SpaceX for building the Dragon capsule. And yet today, for far less money, they have successfully launched Dragon so many more times.
I'd be perfectly happy with cancelling the Starliner and not spend another cent on it. Instead call up Sierra Nevada and see how long and for how much it would take to get the Dream Chaser ready for confirmation testing and a launch on a Falcon 9 and/or ULA rockets.
If NASA wants a Plan B, it's time to thank Boeing for their best effort, but kick them to the curb and bring in Sierra Nevada.