I've never really thought about it like that, but have to agree with you. Harry is completely devoid of character. As someone who fell in love with reading/fantasy as a result of these books, I loved the wizarding world. I didn't really have any care for Harry, or even much for the story that he's a part of - just the setting, and the other characters.

I wonder if Harry's transparency makes it easy for a young reader to project their own personality onto him, and kind of 'roleplay' their way through the series? I think the fact that the wizarding world is 'bolted onto' reality facilitates this - it feels almost tangible. May explain why nostalgia is so high among this particular group - it was an experience, not just a story.

Does this make Rowling a genius? Or do her books just benefit from the side-effect of her writing a bad MC?