Part of HN's convention, especially since there are often more than one link, is to use end-noted links rather than inline ones. This makes the prose easier to read, and still makes it easy to identify and annotate the importance of links.
I suppose it's to make it clear where links go, and discourage trolling... but browsers failing to show you where links go is a failing of browser chrome, and people who are concerned about that can install extensions that make link destinations more obvious.
