10 Reasons The Harry Potter Movies Were A Massive Waste Of Potential

In print, The Half-Blood Prince is about Voldemort. On screen, it's about Snape. That's a fundamental difference that robs the film adaptation of much of what makes its source. Sure, the new Defence Against The Dark Arts professor is the sub-titular character, having a major impact on the protagonist and killing his mentor ahead of the final battle, but the meat of the story is Harry's discovery of the Horcruxes through the memories of Tom Riddle and his family; that's what drives pretty much every step of his sixth year. Heck, he actually believes the Half-Blood Prince is Voldermort for most of the book.

The Half-Blood Prince film is therefore an odd beast. As the penultimate step in Harry's journey, exploring his teenage urges and setting the basic stage for The Deathly Hallows, it does a serviceable job, but in dealing with the wider themes of the book and really delving into the epic story's origins it falls incredibly short.

The Voldemort past sequences are reduced to two flashbacks that paint him as a typically troubled youth, with no time spent on the Gaunts (his pure-blood grandparents) or Tom Riddle Sr. (a Muggle tricked into falling for his mother by way of a love potion). That stuff's much more important than whether Ron had a brief thing for some background student; the point of all this is learning of Voldemort's fear of death (hence Horcruxes), which twists him into a dark mirror of Harry, rather than some insurmountable evil.