>Maybe it's because I grew up on the Internet in places where there was always a sysop, and so I take for granted that whoever runs the server has certain responsibilities. Maybe I understand on a gut level that the opposite of censorship is not academia but 4chan (which probably still has mechanisms to prevent spam). Maybe because I grew up in that wide open space where the freedom that mattered was the freedom to choose a well-kept garden that you liked and that liked you, as if you actually could find a country with good laws. Maybe because I take it for granted that if you don't like the archwizard, the thing to do is walk away (this did happen to me once, and I did indeed just walk away).
I think many people coming to the internet nowadays have had their formative internet experiences on large social media sites, where moderation is both impersonal and rare, to the point that users don't bother understanding it because it's unlikely to affect them, and then if it does affect them, the reasons for it aren't understood and they feel singled out. When these people hear someone talk about smaller better-moderated places, they can't understand the appeal, as if it were proposed to them that a site would be better with more boogeymen.
Youtube et al certainly encourage the free and public flow of traffic. Their business model depends on it. So their responsibility to the public would seem to obviously overshadow the perceived protections as a "private company".
I was also a child of the 80's