So if you have a video site like Youtube, you can take down whatever content you like, and that's cool. However, if you become very successful, and attract many viewers, than it's no longer like that. Now you can choose what you let on your site.
Is HN pro censorship? I mean, stuff HN doesn't want posted here can, and does get taken down by its moderators. You're just not complaining because HN isn't huge?
Complaints about HN editorial policy are not encouraged on HN.
You do raise an interesting point though. Historically, the production & distribution of content intended for mass consumption was expensive, often requiring entire teams to collaborate. The mere existence of a piece of content was subject to filtering, from conception to production to distribution. Most of this filtering was invisible and possibly unconscious, intrinsic to the moral norms of society at large.
The Internet changed that. Content creation and distribution costs have cratered. A solo creator can spam hours of content every week. We are drowning in a quantity and variety of content unimaginable 30 years ago. Media distribution organisations now rely on soft distribution shaping ('boosting' / 'deboosting') and are starting to craft explicit censorship policies. It is very unclear how this will all play out in the long term, though I would caution that explicit legalism can only go so far.
Let's say someone starts a video site where users post vegan recipes. It's a vegan video site. People create an account and can post what they want. Some users post barbecue videos, video on how to skin game, and the site owners remove these videos. If somehow a high percentage of society become vegan and this site blows up, becomes the biggest recipe site in the world, a quasi-monopoly of recipe videos. Do they now have to allow meat videos?