> HN is low on ad hominem attacks, excessive straw man arguments, there is a good amount of polite disagreement, and people are often amenable to being wrong.
That's is due to active moderation, but it's orthogonal to being in a bubble. There are also some very similarly moderated, polite communities on other platforms, even Facebook, but they're still bubbles. People on HN are already self-selecting to an extent, and if you stray to far from the core audience, you'll be downvoted to dead.
That's how the forum is designed to work, but it is definitionally a bubble.
> If this seems no different from the big commercial platforms to you, I frankly don’t know what to say, to me the difference is plain to see.
It is no different to the other well-moderated communities on the other commercial platforms. The only difference is that you like this bubble more than the others.