It's true. Absolute values do not matter, it's just: High end > low end = bright sound and low end > high end = dull sound. Basically, there's no fallacy of perception, it's only perception. But I guess both approaches work. It's just that using just narrow subtractive EQ has always sounded more natural to me.
You are correct but even at the risk of repeating myself: It's complitely a matter of reference points.
We don't mix and create music in a void. We all have our subjective references and memory traces what is bright and what's not. In a mix we rewiew tracks and their attributes against each other.. And to some degree knowing it or not, against other mixes.
If I have a mix running, and everything is fine and dandy, except that the snare could use some high end shimmer, then cutting low end won't do the trick. Then I'd have a thin snare which doesn't have enough shimmer. Crancking the hi-shelf instead indeed does do the trick.
As I stated earlier, it's just a matter of references.. And in context of a mix, cutting and boosting are very different.
It's just semantics. And methodology.
E: Ermz, good notion about the passive eq circuitry. Hadn't really thought that thing through.
But if we consider shear economics, the most economic way to add highs is to add highs.. One can argue that every track has something unnescessary that needs cutting.. And it's everyones own thing how they wiew their sources. The less buttons I need to twist, the better.. Or in reality the less sliders on the screen I need to drag the better. But as I said, it's a free world.