It's a biased forum. HN is run by YC who is currently funding lots of "AI" companies

Internet’s constructive criticism problem is so real. Most people on surface level platforms are indeed fragile because they are always surrounded by a group of people on social. So, when they post something out of their circle. They take the same approach of saying sorry, internet version.

What category in particular? AI? Cryptocurrencies?

Well there was an AI one just recently but it happened with crypto, happens with every hype cycle.