Well, my theory, which I've stated elsewhere, is that you cannot love if you've never been loved, so that Tom is an emotional cripple (emotionally and morally blind is how I put it earlier) simply because he'd never been loved. I think he is so crippled largely because of nurture - but, if he hadn't been a wizard as well as a withdrawn orphan, he would have become a 'normal' sociopath along the lines of Lucius Malfoy or Bagman, etc. It's the combination - lack of normal emotional development combined with great power - that doomed him. And this was NOT HIS FAULT. I do think Dumbledore was far too dismissive of him, but, by the time Tom was 11, it was already too late to save him, IMHO. And that just bothers me terribly.

The thing that I found most chilling in that scene was Harry's deliberate quashing of any pity for Riddle. I thought that was just awful. Both these things - the way Rowling has presented Riddle as a raging sociopath, and the way she's presented Harry as a self-absorbed bully - have me questioning what sort of morality these books will ultimately express.

(But Snape's by far the most interesting character in the books, anyway! ))