It's not. That's complete bullshit, and the On-Board Software Group demonstrated it by being as flawless as can be during the whole history of the Shuttle: as far as I know there was no personal accountability in the OSG, the only thing accountable was The Process supported by a strong culture of adversarial testing.
Personal accountability in such a system brings politics and career advancement in focus and leads to issues being shoved under the rug when inconvenient and energy being expended in finger-pointing and blame games rather than fixing problems.
> So it's not a personal, vindictive "your fault", its an impersonal "the problem is here, lets fix it".
No, it's not. Accountability is very precisely "your fault", that's all it is. That's pretty much the definition of it.