I am not having the easiest time with Kerman's book. I am making a bigger effort not to schmooze while discussing this very intellectual writing.
I'm pleased to see he validates one of my perceptions. Intellectual writing about music tends to focus on form and analysis--the process of evaluating the overall structure of a piece. This process puts all Italian music at a severe disadvantage, since that simply isn't what it's about for them.
Musicologists write about whatever is at hand, and this used to be mostly music of the Renaissance. Audiences are interested primarily in music of the nineteenth century and the neo-Romantics that lap over into the twentieth century like Mahler and Strauss. Musicologists haven't really been worrying about what pictures to hang on the walls of their museum.
(Classical / Western Art) Music used to be about music. Tonality was well established by composers before Rameau came along to propose the fundamental bass. The composer dog created the material for the analyst tail. Now music is about inventing a theory and then composing stuff to fit the theory. The tail is wagging the dog. Evaluation is based on how complicated the theory is and not on whether or not anyone would want to listen to it.
My flaw, I know, is that I can't help editorializing. For me editorializing is the whole point.
Bottom line: there isn't necessarily any correlation between the musical value of a piece and how fun / interesting it is to analyze. I would go to a ridiculous extreme: you are only allowed to evaluate the music if upon hearing it you are absolutely unaware of the theory upon which it is based. You might still like it, but it won't be because the theory is cute.
I, for instance, am well aware that Messiaen composes based on his own complicated theory. I have no idea what this is, but when I listen to his music, I like it anyway.