Rowling's missed opportunity in The Half-Blood Prince

I have spent a lot of time trying to figure out why I think that The Half-Blood Prince is the weakest of the seven Harry Potter novels. What is it about this book that simply does not work?

Sure, I've read the critics who disregard THBP as merely a set-up for the grand finale. And I think there's some merit to that argument.

But I think there's something more.

And I also think that, despite its limitations, THBP also has a lot to offer, a lot of really interesting scenes and great writing.

My analysis is by no means complete at this point but, if I had to say today what most concerns me about this novels, I'd have to say that it's the fact that, for the first and only time in the Harry Potter series, the main line of action in the book does not involve Harry, Hermione and Ron directly. In fact, the novel's central plot -- Draco Malfoy's desperate attempt to kill Dumbledore and redeem his family in the eyes of the Dark Lord -- happens almost entirely "off stage", so to speak.

It's an odd choice for Rowling and, in my opinion, a missed opportunity.

J.K. shows, in the first two chapters, that she is willing to permit her narrative voice to venture far away from our hero, Harry. In fact, Harry does not even appear in "The Other Minister" and "Spinner's End" -- in these opening chapters, Rowling presents the story from the perspective of the Muggle Prime Minister and of Narcissa Malfoy and Severus Snape.

What I don't understand is why she then commits herself so firmly and irrevocably to Harry's point of view from the third chapter onward. Especially when the central tale is with Draco, an interesting and enigmatic character who finds himself facing an extremely difficult challenge.

Wouldn't you have loved to have experienced the entire main plot of the sixth book through the eyes of Draco Malfoy, to understand the pressures he is under, the mixture of fear, anger, and desperation he must feel as he tries to figure out a way to accomplish the task set before him?

Wouldn't that have been a fascinating way to see the magical world in the Harry Potter series?

And wouldn't you have been much more caught up in the building suspense of the main plot of the book?

My point is that Rowling set herself a very difficult task in THBP: to try to keep her reader enthralled in the story without actually permitting us to experience in any real, ongoing way the development of that story.

And I think she, for the most part, failed.

I don't think the brief glimpses we see of Draco, the tiny hints to which we become privy throughout the novel, the suspicions of Harry that are brought to our attention but dismissed by everyone else are sufficient to keep us riveted by that story line.

And I don't think that other things Rowling offers in THBP -- the quidditch subplot, the romantic story lines, even the investigation of Voldemort's childhood -- are sufficient to make up for the lack of a gripping main plot.