devil's advocate: HN is very minimalistic with design.
The problem with many sites is that they're actually quite complex behind a façade of simplicity. Which means lots of wasted space, unnecessary clicks, and not finding what you're looking for.
I'm sure at this point the minimalism of HN probably is a conscious choice (as in, they have consciously chosen not to do anything to the design for however many years, despite, I'm sure, countless offers from aspiring designers), but how it originally came out was surely as a result of the people involved not wanting to put any energy into designing it or writing CSS.
HN is minimal but functional first.