Why isn’t more detail always better?

Simple,  all these wordy opinions , are just that.  KISS principle, keep it simple stupid.  Every one into good sound has their unique opinion concerning detail.  Just  hear your own sound.

One aspect of "detail" that shows up in some systems to me is an unnatural separation of sounds. For instance, in my quest for new speakers I listened to a few very highly recommended models that made a cymbal sound like separate instruments (being struck and the resulting shimmer) and fingerpicked guitar where some string squeaking was front and center and completely separate from the guitar notes. I settled on speakers that (in my system) gave up a little "detail" but, to my ears, kept a smooth and natural transition of sound from each instrument being connected and continuous.

Most observation of details is a bad sign...

Why?

Because in a real experience of natural sound our attention is immersed in a natural way and not alerted by "something" out of balance from the tonal physionomy.

In front of beauty we dont ask for details and we dont focus on details...

We dont set a speakers/room for more "details" but for more naturalness and balance...

In my opinion this vocabulary insisting about "details" in reviewers articles follows from their focus on the gear design for itself not from acoustic concrete understanding in a specific speakers/room...

It is there in their discourse, not only to express their variable impressions about gear but to sell it...

I dont buy gear i try to implement it acoustically in the right way...

Customers want a reason to buy something new : "more details way more" is a winner slogan, true or not , thats does not matter...

If instead of a closed speakers/room i was designing an open amphitheater space, details perception will be a priority instead of balance, as in ancient Greek theater where a whisper is heard with "details" of the voice tone as a goal...

 When i modified my speakers port design, tweeter design and acoustic space i was looking for balance because balance reestablish naturalness with details which are not higher frequencies deceptive accentuation.

Anyway we must work with the frequency range specs of our speakers to begin with  and help them  to reach well balance impression  with and in the room...

Natural detail is always something to strive for.  Unnatural highlighting of a certain group of frequencies that are pushed in your face is not detail - it's highlighting.  If you're listening to a live unamplified performance, you hear all the detail meant to be heard (from a relatively nominal distance).  If you suddenly rush the stage and wrap yourself with one of the performers in a shroud, sure you'll hear primarily that person and their breathing, etc.  But if you step back to hear the whole group, what you will hear is the natural presentation as it was meant to be heard.  Natural detail and transparency is not brightness, nor any other annoying artifact of reproduced sound.  To hear a system that does this correctly is a wonderful experience.  I've had a number of these experiences this past year.