You are a CTO sitting atop very expensive hardware and software. Would you start removing deployment and runtime safety guards (such as a consumer-facing staging environment) because you want to "discipline coders and devops"?
A post-mortem should never be about placing blame on individuals, it should be about identifying flaws in a system or a process.
There are places where post-mortems can turn into blame games, but in my experience such things are counter-productive to actually solving problems. Luckily, there are plenty of engineering organizations that do not make this mistake! :)
