I allways cringe when I hear something discounted as "that's a 1 in a million scenario". If you do the math on departures per year one in a million is a bit on the low side...
depends on the consequences
It it were to be a 100% probability that the consequences would result in an inability to complete a safe flight and landing (somewhere) I would agree with you.
Typically the 1 in a million failure category still has other systems available to get you back on the ground 9 out of 10 times.
In the long run it's easier to work this 9 out of 10 back up redundancy than to try to make a ten fold improvement in the original malfunction causes