At the level of CTO of a major telecom, I don't his firing as scapegoating, it's accountability. The buck has to stop with someone, and the CTO is responsible for the technical infrastructure of the company.
I think parent's point was that absent a crisis the same (incompent) CTO would still be in his job. So if that's what it takes to boot a CTO, who will then land in another executive position, then it's a poor metric for ensuring technology orgs (in old companies) are well-run.
If the current CTO is fired, the next CTO will pay more attention to reliability. This was clearly an organizational failure. Blame free retrospectives have a purpose, but if there is no accountability at the top level, there can simply be repeated failures regardless of the "lessons learned."
