That is not true. Most of her books have pretty good reviews. The only meh one was her first one after HP and that is because it was very unique (people either really liked it or hated it).

Are you sure you actually read Harry Potter? Because it is the characters that make the series, not the world building. Her characters are incredibly 3D except for Voldemort and a few others. There is a reason Severus, Umbridge, Dumbledore, Ron and Hermione are even talked about. They make mistakes, they make great decisions, they have passions and dislikes and things that make them tick. They are extremely realistic. If the characters were truly 2d, you wouldn't see nearly as many debates about Hermione or Ron or even Severus.

Her worldbuilding is what was weaker. Elements were never set. Magic was truly magic with very few rules and thousands of possibilities. I think that is what attracted a lot of people (truly feeling like magic and wanting to get lost in it), but the truth is, she could have done so much more. A magical culture would have been incredibly different than the one she imagined if such a thing existed. She could have made an immense world, but she did not.

That is the reason fanfiction exists because she made a world that is so open and unknown that you can have thousands of possibilities and changes as well as characters that you love and don't want to let go.

 

I've read through them a few times and I found a lot of their motivations and reactions really illogical. She tried to flesh out some characters and backstories in later books but it just didn't hit for me. Until the 6th book Hermione was the only character that came off as well-rounded though Neville seem to have his own character arc that took place mostly off book which would have been nice to see developed a bit more.

Dumbledore's motivation was always suspect which is why it's so easy to write him as a manipulative character in most fics and Snape is the same way; his actions were so all over the place for how it was laid out in the last book that it hurt his character during subsequent rereadings.

I'll admit that it could just be that I disliked how the characters developed but I couldn't help see most of them as underdeveloped; though it may also be that I saw so much potential for development that I found what there was to be insufficient.

 

Besides, I don't think it's just not her not being able to let it go. It's also the fans not being able to let it go. I mean, do we want her to stop writing?

 

Hermione, a "well-rounded character"? I think it was The Guardian's Rowland Manthrope who said that she was still at the end of the series just "swottish, sensible Hermione—a caricature, not a character", and I completely agree, though I like Hermione very much - often the rest is what we ourselves and Emma Watson project onto her.

Back to the topic, though: I feel that it is hard to judge how much an author must be attached to the world they create. Tolkien was hard-pressed to move on from Middle-Earth, and Rowling has made that effort repeatedly, though obviously she keeps relapsing. I think she is probably quite torn between a sort of self-imposed moral imperative (from her books it's easy to see that is quite the moralising person): I must do something else, prove myself worthy in another way, etc. and the comforting, delicious sensation of wallowing in that wonderful world that she has already created and that she is free to develop as much as and however she pleases.

 

It's simple, it produces a lot of money.