Ok, and? I don't doubt it fails in places. That doesn't mean that it doesn't work in practice. Our company does it just fine. We have a high trust, high transparency system and it's wonderful.
It's like saying unit tests don't work in practice because bugs got through.
Have you ever considered that the “no-blame” postmortems you are giving credit for everything are just a side effect of living in a high trust, high transparency system?
In other words, “no-blame” should be an emergent property of a culture of trust. It’s not something you can prescribe.
Yea, except it doesn't work in practice. I work with a lot of people who come from places with "blameless" post-mortem 'culture' and they've evangelized such a thing extensively.
You know what all those people have proven themselves to really excel at? Blaming people.