I feel like this is only partially true.
The majority of the articles, excluding those from large name corps, are simple loading pages. Using primarily the basic HTML and inline CSS. You do have the occasional blog page with some fancy touches, but the majority of the links that I click on while browsing HN has me questioning why, on sub par satellite internet, that HN and a majority of it's submitted posts work when Facebook, Google, Bing, etc.. does not.
I feel it can.
Everything just feels so bloated.