Why do people say Rowling is a good writer

Fuck my friend brings me to this channel full of people who treat the Harry Potter series like they're important modern literature.  And when told that J.K. Rowling is a poor writer, they say shit along the lines of "in comparison to who? Shakespeare!?"

And Jesus, older kids and adults who treat them like they're not children's books.  A friend of mine met a young girl who told her that she "reads mature books, like Harry Potter."

I know Rowling can't write for shit, but could someone recommend me to writers with good style? I need some examples.