Here's my edgy take - I think this sentiment comes from increased usage of HN. If you browse the start of high-voted threads from the front page, you'll usually

Here's my edgy take - I think this sentiment comes from increased usage of HN. If you browse the start of high-voted threads from the front page, you'll usually find a pretty good and calm discussion. If you scroll down to the lower end of a 500 comment discussion page on the Corona virus, you'll obviously find worse discussions and strongly held opinions. I personally don't think there's a decline in quality on HN and to me, the politics end of things seems pretty calm for a large discussion forum on the internet. It's obviously not perfect, but it's as close as a public forum can get.