Statistically, the most popular restaurant in America is Wendy's (excluding dessert and donut shops). Wendy's is pretty good for fast food, but it's objectively not high quality food. That's not to say people shouldn't enjoy it, but if you're learning to be a chef, you're probably not aspiring to mass produce baconators.

I've read two Dan Brown books (Angels and Demons and DaVinci Code). I've read 8 Rowling books.

My criticism of Dan Brown would be that he wrote one book and then wrote it again. It's not great literature, but it's easy to read and doesn't strain the mind with complexity. I understand that he's written four more novels, but I haven't read them. I have heard people say that it's the same formula, and if you enjoy it, there's no judgement here. Reading should be fun and exactly as challenging as you want it to be.

Dan Brown also made absurd amounts of money. Do you know what he thinks about trans rights? No, you don't, because he doesn't use his position of relative privilege to be a shitbag to minorities. Maybe he's a bigot, but I wouldn't assume that of anyone without evidence. Dan Brown created a series of popular books and then fucked off to cheat on his wife. That's all we know about him.

Rowling, by contrast, is a garbage human being. She's actively awful, and goes out of her way to stir shit up and make life miserable for people she doesn't know and will never meet. She is a bigot, and isn't shy about spreading hateful propaganda or punching down. Being a bad writer is the very least of her flaws, but it is among her flaws. When people compare her to other artists who have created masterpieces but had "problematic" personal lives, the comparison is distorted by both the lack of quality to her art and the magnitude of her shittiness as a human. Even if you can separate the art from the artist, it's like picking the solid shit nuggets from a massive steaming pile of diarrhea.