I don't think Reddit's shown us anything of the sort, really. I expect people have a habit of reading too much into this kind of thing.
IMHO the "benevolent dictator" style works better. People on 4chan complain, sure, largely as a consequence of no upvotes and complete anonymity from other users. But they also mostly just "make it work" when it comes to classifying content. On the tech board /g/, there's a surprisingly diverse stream of content that makes its way through. Because there's only one /g/ it all fits into one melting pot and the community is more vibrant and diverse as a result.
I think the same happens here on HN. A lot of different people with different tastes frequent this site. If it was simply "news for startup founders" or "javascript framework news" it would be a lot less interesting.
That is a legitimate force, but it's canceled out by the fact that when you create your own sandcastle, no one comes to to visit it.
You can start your own subreddit, but it will be dead until you build an actual community there and that takes a ton of effort. In the meantime, it provides you no value—all the links on it are ones you yourself added, there's no discussion, etc.
It is (was) moot's website. Other people aren't the ones who set the rules.
Since the design of the site has official topics for each board, you do have to set limits on what's relevant and make new boards when something new comes up. And it's not always possible to make new boards if you don't have mods for them.
In this case, mixing 2D and 3D can be dangerous. It's also a little unfair in that the yaoi board wouldn't be usable for the same thing.
On any *chan style imageboard, this isn't a thing. You can hide posts that you don't like, but by design, all posts are equal. If someone posts something you don't like, your options are to ignore it or respond to it, but it's there, in the open, for all to see.
This, I think, is the better system, combined with the default anonymous posting style of these boards that completely ensures that any post is judged on its merits, rather than the identity of its poster. That's not say that board culture doesn't exist, it does, but it exists purely socially, rather than being a feature of the software. The things I've seen happening on YouTube and G+ and Facebook have convinced me that existence of a coherent identity has zero impact on people's behavior.
I don't know that accountability is a bad thing. If you're so ashamed of what you're saying that you don't want people bringing it up later, don't say it. Or use an alt.
This can balance out the fact that it's an anonymous anything-goes site. Yes, people can say pretty much whatever they want but if they know they will get shamed for it later, it might prevent them sharing the worst stuff.