Yeah, it's the specific nature of his fanbase. This is one of the things with JKR - her problem has never really been with the median kid who likes Harry Potter growing up. It's that a subset of the fandom - the really obsessive ones - were misfit kids who didn't have many friends, HP was their lifeline and they made it a cornerstone of their identity. Some remained superfans in adulthood, with a parasocial attachment to JKR. Many of these kids grew up to be alphabet people, and feel like she betrayed them.
I'm thinking of a gay YouTuber I used to watch who covered different pop culture subjects. One day in 2020 - the date is important - he posted a video about how he didn't like to go out without his Hogwarts scarf and backpack, but now it was painful for him because he didn't want to platform hate.
I had three thoughts in quick succession. The first was, you're taking your attachment to this media franchise far too seriously. The second was, Jesus, this is really sad, you're 35 and you're still obsessed with Harry Potter. The third was, actually it's even sadder, because his mental health had been visibly deteriorating during lockdown. We all went a little mad in 2020.
NG is much smaller as a creator, but by the same token there isn't that huge audience of people who casually enjoy his work. So the superfans, the ones you find on the subreddits, are more important. And NG superfans tend to be girls and young women with vulnerabilities, who've been groomed to see him as the sensitive adult who really understands them.
That's the audience that he's cultivated, and I think that hurts him more.