I feel like this comment is emblematic of a dramatic misunderstanding of blameless post mortems. They're pretty simple; systems that fail can be attributed to teams, practices, systems of understanding, etc which is diametrically opposed to individuals. Blameless culture isn't a culture without blame, in fact there's plenty of blame that should be listed in contributing factors - including the accountable team (if there is one). There's just no, "John Smith did x and y failed" because that's rarely, if ever, succinctly how systems fail.