> Nothing is worse for an airliner than a grounded jet.
Those airlines clearly think the probability of this is pretty low or they would have make the call to ground those planes on their own, but a jet that smashes itself into the earth and disintegrates because of a faulty sensor is probably even worse than a grounded jet.
Not quite because the Airline can turn around and sue Boeing so there is some recourse. Furthermore, people aren't blaming Ethiopian airlines they're blaming Boeing, so the reputation damage to the airline would likely be minimal. The reason why they can't easily sue Boeing over the grounded airplanes is that they don't own them, the banks do.
Those airlines clearly think the probability of this is pretty low or they would have make the call to ground those planes on their own, but a jet that smashes itself into the earth and disintegrates because of a faulty sensor is probably even worse than a grounded jet.