Like the others have pointed out, the site is less information dense and I don't think it solves a real problem. HN looks "old school" but has good design, I think, because I come here to find a good article to read or browse an interesting comment section and the design helps me do that without getting in the way. Mostly I never even go to the second page.

Also I love HN's slightly yellowish background. It's better than a whole white bg.