Nah, any technique that gets people thinking about root cause analysis is worthwhile, but like most lean techniques they require a level of psychological safety in the organization to be effectively used.
Exactly. No methodology can overcome a low enough baseline of trust. Over time, cynicism gets equally distributed and the justification for literally any process or technique becomes vapid corporate kool-aid. You're just left with thinly-disguised attempts to assert power met with toxic resentfulness.
The way I see it, there's a spectrum of trust that goes from one extreme where almost no process works well, and the other extreme where almost any process works well.
So there's the easy discussion of how your technique is supposed to work, and then the hard discussion of how much trust it requires of the people involved.