I find that I edit myself with humor much more than other things, especially on HN. Interestingly enough, this seems to have carried over to real life, with not such good results. Sometimes you just need to be yourself.
There is a principal-agent problem here as well. HN (or any other site) exists for some sort of narrow market segment. I know I came here because I wanted to go to one place to search and discuss items of interest to startups. From that idea the site has evolved into "stuff that interests hackers", mainly because there is only so much material you can mine using the narrower niche.
However, and this is interesting in terms of growth-for-content-sites, the reason I stayed wasn't because the topic area widened up, it was because then it became a place to hang out with other hackers in the startup community, which I _also_ found useful.
But once it became a place to hang out, my goals and the site's goals diverged. The site's goals is still to provide some kind of content niche that it does well. That, after all, is what makes it useful. My goals, however, are more like the goals anyone would have in a community: camaraderie, humor, exploration of common ideas and problems, understanding of motivations, discussion of mores.
There's not a lot of room between those two goals, but there is some, and I wonder if over time the effects add up.
(I don't know the answer. I was just wondering)