When I was a kid I loved Heinlein, Asimov, Piers Anthony, Howard, Lovecraft, among dozens of other then popular scifi and fantasy authors
Heinlein is some weirdo libertarian fascist
Asimov hates women and was a notorious sex creep
Zanthony is a pedophile and his books are full of creepy shit
Howard was staggeringly racist
Lovecraft is also famously racist.
And that's just the ones off the top of my head.
At some point I learned that all these guys were creeps, came to terms with it, and moved on with my life. Like an adult.
So all these people whining that "oh no I can't let go of my childhood!!!!" fill me with contempt. Many of the great shit-head scifi/fantasy writers of the 20th century made great contributions to the field of fantasy and sci fi. Our conception of robots wouldn't be the same without Asimov. Heinlein changed military sci-fi forever. Howard's Conan had a lasting impact on fantasy fiction far beyond what was merited by his mediocre writing. Lovecraft introduced the notion of Cosmic Horror that continues to push back the borders of science fiction today.
Rowling can claim none of that. Her wizard books are extremely mediocre with poor plots, flat characters, and no new ideas. Their popularity is the result of a then unprecedented marketing campaign, not any particular artistic merit. They're entirely pedestrian and forgettable and there's no reason to read them except as a historical curiosity or a case study in successful marketing of children's literature.
I gave up many genuinely influential and talented writers when I realized that they were jackasses. There was nothing riding on it. No one is using Lovecraft to justify violence against Inuit people or something. I just found out they were jerks and said "Well shit. Guess I won't recommend these to kids anymore".
And all these jackasses have the audacity to say that we should respect their love of the mid wizard book beause it's so important to them?
I still recommend some of Lovecraft's work, and Asimov's, and other shitty people's. But always with warnings, with the intent to discuss their flaws and the way those flaws creep into their work (or, sometimes, take over the work wholly) and the way that those works can still be valuable and cool and worth looking at despite those flaws in author and work.
The problem with Harry Potter is it doesn't really have any redeeming qualities. It is, as you say, worth nothing more than good marketing. I wouldn't recommend them to anyone mostly just because they're not very good, even with Rowling completely out of consideration.
If they were good? I don't know, it'd be a different story.