Arguably, the existence of nuclear reactors which don't fail safe under any contemplated crisis is a hardware bug. It's possible to design a reactor that can be ruptured by a bomb or earthquake, which will then dump core into a prepared area and cool down.

This kind of physics-based safety is obviously not possible for airplanes.

What triggers the core dump? Humans? Software? Are there detectors integrated into the walls?

Physical rupture of containment.

If all electronics fry simultaneously, then the reactor core cools in-place.

I should have said “commercial airplanes are among the most important and critical things that use software.” It’s obviously difficult to determine the objective most important use case.