It seems like I did not explain myself well enough in the article.
I don't think for a second that J.K. Rowling wrote any of her books with harmful intent at all.
I intentionally choose examples that were somewhat nitpicky (although I do think fat-shaming and teaching standards are important issues) because I felt that it better illustrated my point.
The point I was trying to communicate is that no work of fiction is perfect, even the great ones. And rather than focusing on the imperfections, we should focus on the positive aspects. That way, we can appreciate the work for the beautifully imperfect work of art that it is.
I really love your point about good parenting and good teaching. The importance of both can't be understated. The parenting and teaching of today literally shapes the future.