It was anticipated it would fail eventually. They will review this failure and use information from it to bolster their refurbishing program.
> For comparison, if a plane crashed after 23 flights everyone would assume it was a factory defect.
Planes are meant to fly well more than 23 flights so that's a bad comparison.
No other booster has flown more than 23 flights, this is unchartered territory.
Even by the FAA’s standards for passenger aircraft (Not an experimental Rocket) that’s incredibly unlikely.
If the airline attempted to take off with it, yes, that merits a grounding.
As I stated in the part of that sentence you omitted, everything fails eventually. It is very reasonable to expect a better estimate than that for a human spaceflight. If something fails, you need to know why it failed, it doesn't matter if it flew once, 23 times, or 2300 times.
> Planes are meant to fly well more than 23 flights so that's a bad comparison.
The point of the comparison is that for aerospace hardware 23 uses is not decrepitly old, and a manufacturing defect can easily take that long to cause an issue.
> No other booster has flown more than 23 flights, this is unchartered territory.
And it will remain uncharted territory if the reaction to a failure is "eh rockets just aren't supposed to work after that point."