You are correct it is a great introduction to how to use linux to serve files and a key use case for the Pi. But why is it on hacker news?
/r/raspberry_pi is basically overwhelmed with these type of articles. It also features a huge number of posts related to raspberry pi cases. Overall it is fairly disappointing.
These articles are much less informative than explaining how to google for this information.
I think HN is a good place for hackers of all shapes, sizes and experiences.