Acceptable loss of crew event is like 1 in 250 (can't remember the exact number). They can't quantify the probability of failure, so not putting them in Starliner is the right call.

Yep, 1-in-270. https://en.wikipedia.org/wiki/Commercial_Crew_Program#Spacec...

1-in-270 is overall probability threshold for a 210 day notional ISS stay.

For the journey home from ISS to Earth, the probability threshold is 1-in-1000. Likewise, it is 1-in-1000 for the journey from Earth to ISS.

The riskiest part, which increases the probability from 1-in-500 to 1-in-270, is the ISS stay – the extended stay in space is faced with a continuous risk of micrometeoroid damage.

Its kind of grim to think a trip to the ISS has a 1:270 chance of death just from the unavoidable roulette of getting zinged by a micrometeroid.

1/270 is the total risk from all causes. Just the risk from micrometeoroids would be (at most) 1/270 - 1/500, which is roughly 1/587 (0.17%).

Welcome to space, it's really fucking inhospitable and will always be.

Because every Starliner flight has had serious problems but the same cannot be said of the SpaceX vehicle, which is in addition more proven.