MS Sql Server not even mentioned. This tells us there is a whole world almost totally omitted from discussion on HN: "Enterprise"
Oracle isn't in there either, which goes to show how much of a bubble HN actually is considering MSSQL and Oracle are #1 and #2 in market share.
I used MS SQL and Oracle at my last job, but what's there to say about them? They've been around forever, are stable and get all the same table-stakes feature updates as everyone else. Start-ups avoid them like the plague because they're so damn expensive, you won't be running either on your phone or an embedded device like SQLite either.
I do think it's an SFBA / generational bubble. We have plenty of boring, expensive software projects that someone will always bring up in a HN thread. For example, every time there's a thread on PCB design, you have some folks talking about Cadence. What's there to say about Cadence? Well, first and foremost, it costs a lot. Otherwise, it lets you design PCBs. But there are people here who pay for it, use it, and want to talk about it.