There was actually a blog post making this argument a while back. I think it may have been submitted here, but I can't find it because news.yc only lets me see my last 180 saved stories. It goes through the numbers though and makes a pretty good case that getting "only" 2,000 subscribers is actually extremely difficult. (There was something vaguely similar submitted only a month or so ago, but the one I'm thinking of is from much longer back.)