This isn’t social media. Nor is Reddit or other similar sites. The main criteria is “social”. That means human relationships, friendships, family, etc. I don’t have any sort of relationship with anyone on HN, Reddit, etc. We are all strangers passing in the night. Basically anti-social media.
But it’s not really. What we’re doing here is by definition social. It’s just a different flavor of social. It’s surprising to me that you think talking to other people on the internet is somehow anti-social.
It's not anti-social, but it is anti-"social media". HN has made a lot of wonderful design choices that prevent it from becoming Reddit or Twitter. Hiding points on comments, not showing indicators for replies (making it easier to move on), solid moderation that allows for diverse viewpoints while avoiding a lot of toxicity, etc.
This is not considered a social media site. Just because someone creates a definition of what they think a term should be defined as to group all social interaction together is bullshit. One could say because my program here makes bank transactions automatically for me would be deemed social media as well, because the media of a mass said so. Email and a password are grouped now as social media by your terms and the masses. This is merely a place to receive information based on links that people provide as news. I am just going to group you into the idiot group that thinks everything internet related is social media.
It's really gross to consider simple forums to be social media, but I guess you're right per the definition.
Usenet and IRC are social media. MUDs also social media.