The same argument could be flipped on you! I believe you post a lot on Hacker News, but you don't own the code, servers, etc. You are a volunteer commenter. What if someone blocked and deleted all of your comments? Wouldn't you feel the slightest bit of loss?
Actually, that is one of the things I rather like about HN. The "loss" is built in: after a couple of days, nobody is going to read or respond to any of my comments. Everything I write here will effectively disappear several days from now. And that, somehow, is very refreshing: I don't have to worry about posterity or the future.
HN is my way of indulging in the present. No plans, no worries, no future. Very relaxing.
It's also a way of tricking myself to write. In high school, I never liked writing much and, consequently, was never much of a writer. Now I like it more; hopefully my writing improves correspondingly. HN is obviously no way to become a writer, but that is not my goal: I just want to be able to write clearly, nothing more, nothing less.
If I was doing something more lasting, I would not want to trust a single entity. This is why all my code on GitHub is also backed up at home with the most important projects also backed up on my school account: losing that would actually be painful. Losing my comment history here? Trivial.
I would feel freedom. At that moment, my involvement in HN would come to an end, and I would find another way to use the 2 hours or so a day I spend on it. Think about what I could do with 700 hours/year.
That's like telling an alcoholic they don't have to drink. There's a reason why I've _never_ even glanced at Reddit. And I also took the plunge and deleted my Facebook Account. I lost three months of my life to Tribal Wars. I keep my time on HN to a couple hours a day - and it is my principal news source (No Techcrunch/engadge/verge/gizmodo - unless they are linked) - but if a moderator came and said "Deleted, return never again!." - I would embrace it. Not saying that's true for anyone else. I am implying that someone who spent the better part of two years managing a sherlock fan site, only to have it go "poof!" - shouldn't feel bad whatsoever.