re: JK Rowling is not a good writer or story teller

She didnt write the cursed child. To my knowledge she isn't heavily involved in writing the films either. She may be giving general plot points, but I don’t think she’s involved with the script.

Harry Potter is definitively the most loved book series of the past 20 years. Sure it has its flaws, but it’s still an incredible series. Just because it is less esoteric and easier for children to read doesn't make it any less of a classic. It’s easy to write a book liked by a specific age group. It’s hard to write a book universally loved by people of all ages.