I'm also not sure it would hurt to have you ban a quarter of Discussion, but I'm a lot more optimistic that nothing bad goes wrong if you consistently ban everything this horrible.
This was a concrete estimate made by looking at the most recent 35 posts, with quality threshold that happens to be close to how I perceive Will's post. (It doesn't appear to me exceptionally horrible, and I expect there are other posts that appear exceptionally horrible to me, but not to you. So if I only deleted the posts that seem to me exceptionally horrible, Will's post in particular wouldn't be deleted.)
I agree that it's better for that post to not be on LW, but banning such things is not standard procedure, and people don't like it when moderators do surprising things.
It is not clear to me that this should be an important consideration in restraining moderation.
To clarify, the "surprising things" I consider dangerous are decisions that ignore policy, not decisions that follow a policy that's unusual. With a policy of unrestrained moderation, individual acts of moderation won't be as surprising in the sense I intended, for example they won't provoke big discussions focused on them, especially if those too are against the rules.
As a constructive suggestion, I think that as an alternative to permitting deletion of posts, it would be better to give an x10 downvote hammer (in addition to the normal one; and perhaps only for posts) to all users with Karma 10000, or something along those lines (maybe in some form that doesn't have as much impact on poster's Karma, to minimize trauma). This at least would require multiple people to agree that something is horrible for it to be effectively removed.
Alternatively, let people choose to make their votes public, then provide a way for people to provide an algorithm based on that data to filter/mark posts.
My stupid fanfic chapter was banned without explanation so I reposted it; somehow it was at +7 when it was deleted and I think silently deleting upvoted posts is a disservice to LessWrong. I requested that a justification be given in the comments if it were to be deleted again, so LessWrong readers could consider whether or not that justification is aligned with what they want from LessWrong. Also I would like to make clear that this fanfic is primarily a medium for explaining some ideas that people on LessWrong often ask me about; that it is also a lighthearted critique of Yudkowskyanism is secondary, and if need be I will change the premise so that the medium doesn't drown out the message. But really, I wouldn't think a lighthearted parody of a lighthearted parody would cause such offense.
The original post has been unbanned and can be found here, so I've edited this post to just be about the banning.