Oh you sweet summer child
The NASA space probes are constantly uploaded with new software that has greatly increased the scope of their mission.
If they didn't make "safety" right from the first time, why do you think they will do it better the second time, when the fixes are more expensive and the time pressure is enormous ?
...all of which is just an excuse to show this great picture of Margaret Hamilton [1] lead developer on the Apollo guidance system standing next to (and slightly shorter than) the printouts of the source code https://en.wikipedia.org/wiki/File:Margaret_Hamilton_-_resto...
[1] Who was admittedly quite short apparently
I've worked on some interesting software with lives on the line as well and the amount of test code absolutely dwarfed the functional part. I wonder whether at the time of the effort you linked that was already common practice and if it was what the fraction of that code was tests.
Assuming she's 1.65 meters tall and 66 lines per page (quite common back then), at 0.2 mm thickness per page that's 8K pages times 66 lines / page is ~550K lines. Pretty impressive!
The idea that one can create complex bug-free software is a fantasy. The correct mindset is to learn how to deal with failure. (This is how airliners are designed.)
This does not fix any QA process that is broken. And frankly you should not need to update any control unit firmware after it is sold. The fact that they're even doing this is broken.
Unless your Mac is somehow attached to 5000 pounds of metal going 65 on the highway, the same standards should probably not apply.