Ask HN: Why is hackernews so old-fashioned?

As a web developer, it's always seemed strange to me that a tech incubator would have such an old-fashioned website.

It's nice in some respects - pages load extremely quickly and the layout is compact and to-the-point. I was starting to think it was just minimalist by choice and not actually outdated, but then someone mentioned that async requests are done through an <img> tag instead of ajax, so now I'm wondering what the story is there?

Has it just been left alone because it's not broken? Or because they're worried people would get upset about changes? Or for maximum backward-compatibility? I'm not complaining; I'm just really curious.