The publicity around Battle Hymn of the Tiger Mother focused on author Amy Chua's parenting style, probably for the shock value (see Anne's blog post: "It's Ten PM. Are Your Children Practising Violin 'Til Their Fingers Bleed?"). Given that most readers wouldn't pick up a book about the world of classical music, it's a stroke of marketing genius. And yes, a book about a household where the piano has teeth marks is going to be interesting.
But so are the parts about why the violin is much harder than the piano, and the inside view of music lessons with famous teachers. The author's enthusiasm for classical music must be contagious - I've checked out one of the library's Teaching Company music courses (BHPL has several different ones, all on CD).
The end of Battle Hymn has - for lack of a better word - plot twists that humanize the author and make the book take on a carpe diem philosophy. As the author says on page 63, "... the best way to protect ... children is by preparing them for the future, letting them see what they're capable of, and arming them with skills, work habits, and inner confidence that no one can ever take away."