Oops, I didn't consider that it was sarcasm. I thought it was mocking the actual average HN perspective (which I'm dissenting from, challenging that average user to explain themself).

It was not intended to be sarcasm. It was indeed a criticism of the average HN perspective which I find far removed from the perspective of a given user.

Now I’m even more confused. Do you think Usenet, mailing Lists and forums aren’t social media?

I do, but I don't think a lot of people on HN consider them as such, which is a fun jab at the hivemind. You'll see a lot of threads where people deride social media but say "HN is the exception." Maybe that's what you meant by sarcasm, and if so you're on the nose.