DS: This method of exposure is really very similar to adapting the Zone System for use in digital. If you think of the histogram as a Zone Map, they are exposing to maximize the amount of information recorded. IMO deciding what your
subject is and how you want to expose THAT (typically Zone V) ahead of composition is another way of approaching this. I think this kind of technique ETTR is particularly useful in landscape-type scenes, where you want as much information (shadow and highlight) recorded as possible.
This is also of course how HDR photography works, except the bracketing overcomes sensor limitations. The downside (IMO) with HDR photography is that it is so very often abused and overused, and because of this it gives a scene an artificial quality.
HDR is like the Autotune of photography: It mitigates limitations or mistakes in exposure (pitch), but can introduce that plasticky feel.
My personal approach is to try to expose for the subject. I record in Raw, and then when in PP I look at and adjust towards histograms that maximize dynamic range (Zones), while keeping the aesthetic I want. Sometimes black shadows and blown highlights are pleasing
As always, photography is an art of the personal...so what works for me may not work for you or others. Everyone's mileage may vary!