Why is there this trend of people trying to defend Rowling's bad writing and/or act like they knew it the whole time, and really doubling down on it?

I cannot help but notice this trend a lot, sometimes even on this subreddit but especially on r/TopCharacterTropes. When pointing out problems with Harry Potter and such, you'll suddenly see people try to claim that it's meant to be just for kids (the same people that claim Harry Potter is a mature series and praise it for that), or if you bad-talk the ending, they'll claim that it's realistic and that's how society works (and if you go the way of realistic implications, then they'll claim it was never meant to be that. And while these are some really specific moments, overall I notice this trend of religiously defending the writing of Rowling, or trying to make it not as bad as it seems ("it wasn't her intent", or like trying to find a way to still praise/support her while circumventing the queerphobia), especially with people getting angry over the movies and in a vain attempt to try and act like the books are the greatest thing ever.

And while you could argue this is in any fandom, it feels different for Harry Potter, with a taste of pseudo-intellectualism and always wanting to be right/the perfect hero no matter what. And also sometimes cult-like vibes (no seriously I am not joking).

Why is this?