London, May 19 : They've sold more than 400 million copies worldwide, and made author JK Rowling an estimated 560 million pounds fortune, but that still hasn't stopped Children's Laureate Michael Rosen from branding the series 'a bore'.
The reason - the narratives are too complex and challenging.
He adds that another reason why the books "don't grab him personally" is because the sinister themes would leave most young children confused.
"I am distant from them whereas I read some kids' books and I get quite drawn in emotionally to them," the Telegraph quoted him, as saying.
"Whereas authors like Enid Blyton are hand-holding narrators who lead children into safe environments, J. K. Rowling is more of an adult writer in that she leaves you hanging in the air at the end of chapters with no idea what is going to happen next.
"Figures appear and you don't know whether they are a goodie or a baddie. You would think, traditionally, 'That is for an older reader', because young children more often than not cannot cope with that.
"My seven-year-old daughter watches the films but they tend to spell it out a bit more. I have not read the books to her; you do not want to bore your kids."
However, he does acknowledge that the series deserves credit for introducing a generation of children to reading.