I understand what you're saying, but there are several reasons why I still think a community would be a good thing. The first is that it will help with my job of selecting content. Currently the process involve myself spending way too much time on sites like Hacker News and Reddit, and having a discussion board where people can post content specifically for the inclusion on the main site would help immensely.

Secondly, one of the defining features of the community (hopefully) will be a high signal/noise ratio. The tentative name for it is "Silence" to emphasize that. The main site already features several essays that should help with having the right mentality when participating to keep S/N high.

The plan is to have the link to the community portion of the site buried in the Communication section, so that people will already have read a good amount of stuff before finding it, and also explicitly telling them to read that whole page before participating.

You said yourself that if LessWrong went offline you would end up procrastinating somewhere else. I think this is true to the extent that there are other things you can do, that you would also be able to justify to yourself the time spent doing. You would never spend as much time watching cat videos as you do reading LessWrong. The problem with sites like LW is that they often give you the illusion that you're getting your time's worth even when you're not. There are many of them, so you'd have to black out all websites like that at the same time, but it would probably be fine to keep the cat sites up.

What I'm trying to say is that, given that there are already several websites with the set of characteristics that are needed to make you procrastinate, having one more or one less won't make a difference. So no, I'm not too worried about that. Furthermore, my site features a lot of content that contain that same sentiment of yours. For example the Noise section under Journalism or Confessions of a recovering lifehacker.

Anyway, I haven't elaborated on what I mean by building a community because I have a lot in mind and I'm not sure what I'm going to tackle first. I despise actual social networks like Facebook, Twitter and LinkedIn, and I have ideas to make better alternatives. I also want to make something for children, because children have a lot of time and it would be well spent reading my collection of essays. A social media site that covers a broader range of subjects while keeping a high S/N and a Rationality flavor is something that I would love to have so I don't have to suffer with Reddit and Metafilter, etc, etc. The one thing I want ASAP is the discussion board mentioned in the first paragraph.