There is no entry following this one

I'm reading theweaselking's LiveJournal. I use the RSS feed to tell me whether there's anything new, click on the oldest entry, then click on the "next entry" arrow repeatedly until I run out of posts. I do this because I want to see the comments.

Inevitably, when I click on the "next entry" arrow on the most recent entry, I end up with an error message saying "There is no entry following this one".

Why? If LiveJournal knew that there was a given entry was the last one, why give me an arrow to click on?

(Similarly, if there's a friends-only post following the post I'm looking at, why complain that I'm not authorised to see the post? Why not just take me to the next post that I am allowed to look at?)