About your last point, you hit the nail for me. HN is 4chan without the pure chaos, with people talking smartly. Here you can find all the political spectrum (including nazis), but people will try to not be as inflammatory as 4chan users (most of the time, at least). There's no limit to what people will defend here. I don't think that it's something necessarily bad for HN, but it opened my eyes about how tech billionaires are a bunch of HN users that got a lot of power.
Its really ironic that I read the term radicalism in Hackernews as being against tech billionaires and this is the sentiment that I usually see here reasonably (atleast in my opinion)
But your comparison to HN radicalism to equating tech billionaires as HN users themselves flips my whole comment upside down.
I don't know much about the political biases here but I like to think that most people are pro open source and that they dislike the manipulative characteristics deployed by some infamous tech billionaires or those companies. Usually I think that's the case unless of course someone might have a bias themselves I suppose.