I can't speak for other art forms, but when it comes to lyrics, in my experience, when folks do the "why does this work? why does this sound good?" thing, they're not downplaying the artist's effort – they genuinely can't articulate why it works, because they have no concept of scansion. They can intuitively feel that some lyrics "fit" the music and some don't, but they couldn't explain why to save their lives, and when they try to write lyrics of their own, there will be absolutely no relationship between the syllable count and stress patterns of the words they come up with and the rhythm and metre of the music. They can tell their lyrics sound like shit and don't know why – from their perspective it's pure magic and people who can make it work are wizards.
