Yeah, criticisms have been used against it like being dark and having graphic violence in it.
I don't get why people criticize it so much.  But it for sure helped to shape it.  It included concern with a dark tone and had a depiction of graphic violence.
Harry Potter is one of the enduring books that has ever been written in the modern history. Words can describe how fascinated I am by this novel That's neat to hear, are you a fan of its author too? J. K. Rowling? I really like her. J.K. was truly imaginative and full of dream-like creativity in developing the characters. Do you know the story gist as well? Yes, its about Harry Potter and his friends and their lives. What else do you like about these novels? I really like the main story arc of the story but its been a while and I'm embarrassed I'd mess it up summarizing it for you, unless you already know it? Actually I do, isn't it about how Harry has to deal with the dark wizard Voldemort? Yeah, I really liked how J. K. managed to keep that story going even over 7 books, heck nowadays it seems writers can't even hold a 2 episode tv plot point. You seem quite knowledgeable, do you know how many books were sold? Can you believe that more than 500 million, yes 500 million copies of the books have been sold around the world? That does not surprise me at all! I bet it got its fair share of haters though, 500 million and there's always that 1 contrarian
The series has also had its share of criticism, including concern about the increasingly dark tone as the series progressed, as well as the often gruesome and graphic violence it depicts.