Ironically I found that page hard to read. I think it might the constantly having to switch my eyes back at the end of a line breaks the mental flow of the sentances. Anyone else experience similar?
On my laptop screen a single line is about 35cm long and individual glyphs are about the size of those used in my 3 year old's book. In fact, this is exactly the problem with all such websites - they all look like kindergarten books. It is as if they are trying to speak to you s-l-o-w-l-y because you are both dumb and legally blind.
FYI, you can get a plug-in such as Stylish for a lot of browsers that will let you override styles for specific sites. For lightly formatted discussion sites that I visit often, I typically set a font and a (max-)width for comments and related material that I find comfortable.
For HN, I personally set a max-width of 700px on .comment and pre blocks, to go with fonts of around 18px. If anyone new to Stylish wants the exact overrides I use to paste in verbatim, feel free to ask and I’ll look them up.