So reading about this my current company sounds exactly the same. And the one before it, and the one before that.
Critical issues happen with customers, blame gets shifted, a useless fix is proposed in the post mortem and implemented (add another alert to the waterfall of useless alerts we get on call), and we continue to do ineffective testing. Procedural improvements are rejected by the original authors who were then promoted and want to keep feeling like they made something good and are now in a position to enforce that fiction.
So IMO the lesson here isn't that everyone should focus on culture and process, it's that you won't have the right culture and process and (apparently) laws and regulation can overcome the lack of culture and process.