I agree. There's nothing wrong with what the guy's doing. He'll learn a lot from it, and I wish him well. It's also good to be writing about the things you do, successful or not.
Agreed it isn't newsworthy, but it can be inspirational to a reader who hasn't had the 'guts' to take this leap. I'm sure a lot of people reading HN think about writing a new OS it's one of the archetypes [1]. So seeing someone take the plunge can be liberating. Seeing him get slammed on the site can be de-motivating so I was hoping to counter some of that. Back when I was doing a Java based OS I spent a lot of time reading the basic kernel in eCos which had a very nice packaging an build system. I would not have invested that time if I hadn't been aspiring to other things.
[1] Programmers seem to come in 3 archetypes; the systems guy who dreams of building a new OS, the language guy who dreams of building a new programming language, and the networking guy who dreams of building a new protocol. Some folks are parts of all three, I once thought if you wrote an RPG where the characters were coders these three areas would be where you would add skill points.
"Not newsworthy" is a valid critique of a submission from a news site, but you should avoid making it of blogs like this. The author didn't submit their own post. I know you're implicitly criticizing the submitter (and the voters), but that's a subtle and annoying distinction.
It's not even remotely newsworthy, though.