See there you go, accusing people and putting words in their mouths. Nobody said kids were the problem (or even "a" problem) but not every kid feels the same way and that sometimes has little to do with parenting.

But feel free to go and accuse everyone of being a bad parent because things worked out for your niece. I know more than a few people who were damn good parents and their kids did eventually come out to them, but it took awhile and some digging to get to it while in the meantime those same kids were experiencing real issues in their social life because of it but their parents were unaware of why (though on most cases they know something was off). Once they finally got through it the dialog with their parents was great but it took quite awhile and needless suffering in the meantime. In one case the child was concerned that a rather religious family member (not the parent) would find out and ostracize them. When that family member did find out over the longer course they were actually very supportive, if a bit confused.

Having something in policy one way or the other is idiotic. Some kids might get beatings for having low grades, but that doesn't mean we don't decide to keep parents informed about academic performance, it means we should report unsafe home environments and use judgement in other cases.

If the teacher believes there's a real risk of harm then that should not feel compelled to share that information by gov't, but at the same time if something is potentially adversely affecting a child they shouldn't be compelled by black-and-white policy NOT to engage the parents, and early interaction may benefit all sides.

The "all kids who don't want to talk to their parents must be raised by abusive rednecks" is just a shitty argument. Even adults sometimes have hidden fears or worries that aren't bounded in reality, but allow unrealistic "what if" scenarios to hold them back. Kids are in a worse state with less personal experience and a bombardment of other people's opinions, situations, social media and many other factors than can bring anxiety even in the best of home environments.