Not getting fired is not the same as isolation from consequences. People who make rational decisions and achieve results get opportunities to make more impactful decisions. People who don't get results don't get more opportunities - or maybe find themselves in a situation where the scope of their decisions (and blast radius) is limited. Firing is for misconduct or when someone has no value to offer. It's more of a spectrum than a binary thing.

I can't speak for how these particular executives were handled. I've never worked at a place where people were quickly fired for mistakes unless it was something extreme. It's usually based on track record rather than a single thing. Most employers understand that if they fired people for making mistakes they would run out of employees very fast. On the other hand, someone who learns from a mistake probably isn't going to do it again so you may have a better employee than a hypothetical replacement. It's also generally understood that people with a large scope of responsibilities have a large blast radius when things don't work out. It just comes with the territory and it's not exclusive to the executive suite.