Actually, it is useful, because everyone is going to the same page, so the community's attention is focused on a few items at a time. This is what enables conversations to happen. If instead you just have a catalog of code, the community's attention is dispersed throughout the site. That's fine if the site has the popularity of, say, YouTube, but that's not the case here. There's extremely limited attentional resources, and they need to be focused.

Just as with reddit or hacker news, if I haven't seen some piece of code, it's new to me, so it's news. There's no reason to apply some traditional standard of news and then say code submissions don't fit it. I read reddit or hacker news because like-minded people canvas the web and collect awesome links. Often it's "news" but often it's not. This is a case where most items may not be news, but the hacker news UI is still useful.