Something about this makes me cringe. Not sure exactly what. I think it's the idea of "iterate fast and build awesome software" as it pertains to high integrity systems.
You don't iterate fast or slow when dealing with this shit. You do it at the exact speed you need to to fully understand the domain, failure modes, validation processes, etc. Similarly, you don't write "awesome software", you write exactly what is needed -- nothing more, nothing less, and what is there needs to go bang every time.
There is no reason to believe an enthusiastic day-tripper who starts getting bored when the grueling FMEA, design validation, etc. starts to kick in is a better choice than the salaryman who's prepared to do what needs to be done for the next 10+ years of the product lifecycle.
I say this as somebody that worked on an unreleased product that was on the cusp of safety critical and am glad that it didn't go to production in hindsight. It desperately needed less "awesome" software and a lot more "paperwork".