The author's name is pretty inconspicuous (randomhack), but if it was like mine, it would be tied to a bunch of other online websites with the same name/identity. Maybe he doesn't want that to be indexed on Google. There could be a variety of reasons. Anyways, IMHO deletion of one's account should be possible for every service for any reason.
It could. If you are unhappy with something in particular maybe it can be fixed. I just think each and every one here is very valuable and if they must leave, they are also taking away their contribution (submitted links, comments). So if there is something that can be done to avoid it, then why not?
Now on the flip side, if you are firm, then I totally respect your decision and you should be able to delete your account as well as all your links and comments.