> "5 Why" style analysis is really easy to steer toward whatever you want to blame.

This is the big issue. Ideology, bias and self-interest creep in and you can easily end up blaming whatever it is that you personally disagree with.

And that's to not even mention the "unknown unknowns", which by their very nature cannot be factored in to a "5 Whys" process, no matter their real world relevance to the problem at hand