This. The unsuccessful ones simply won't speak up, because they know that they'll get eaten alive on any Internet forum. Or they will talk about education in general terms without mentioning their own kids.

If your kids are struggling, it must be because you are immoral, lazy, have bad "culture," etc. Internet discussions of parenting always devolve into success theater.

But the kids themselves will eventually speak up. If you follow HN for a while, you will also read stories from a surprisingly large number of successful people who had deeply negative experiences in school as kids. I got through high school by pretty much ignoring all of the "content" and doing well enough on exams to get OK grades, plus I had fairly high test scores, and didn't aim too high with my college applications.