Fortunately, rarely triggered bugs are rarely triggered, so you have time to patch the software before the second smoking hole.
Doesn't stop the first hole of course, but then you can't have everything.
When humans make a smoking hole, history proves that another one and another one will follow until they invent something to stop it.
EGPWS for example!
An entirely automated system that checks if the pilot is being a prat and tells him what to do to not die.
Sometimes, because it cannot actually take control off the pilot, they still manage to hit the ground, but mostly when they act as controlling monkey for the fully automated system they don't crash.
It's very effective and one of the reasons CFIT has dropped spectacularly.
TCAS
Another example.
It tells the pilot what to do. It requires no thought, in fact it specifically says not to think, just do what you are told and you will not hit anything.
Again, it would be easy to integrate with the autopilot and then it would be even more successful but pilots might complain.
Do you notice a trend?
We make an automated system that requires no human thought and things get safer?