Whether it actually works for those companies (beyond a placebo-like effect) is open to question.

But the bigger point is that - even assuming for the sake of argument that these questions actually do "work", on some leel - they've become such a huge fad that people are just adopting them solely on the basis of authority, without intrinsically understanding why these questions work, or more importantly, how to interpret candidates' responses to them

In other words, they're just following a script. I wouldn't say quite it's on "blind faith", per se (because the companies do have some reputation). But it's not much better than blind faith. Such that this precious quote of yours, from just a few days ago, seems quite apt here:

This practice of blindly adopting ideas just because they work for Google needs to stop.