Early on, Paul mentioned how sites will redesign and lose their charm, like the quaint restaurant around the corner which was quirky but always booked, and then expanded, tripling its size but also destroying its character, and then went out of business. He didn't want that to happen here.

Personally, I disagree. I think this place got big anyway. It's not the same as it was when it started, and a redesign would reflect that.

I built my own front-end for hacker news and it supports dark mode. However now my problem is to comment (like this one) I have to switch back to hacker news itself, and the flipping back and forth from dark mode back to light mode is intense; I am still looking at after-images from the dark-mode text right now. So I will definitely support a native dark mode option :P.

Lack of dark mode is the least of the sites UX problems. HN fails hard on all vision-related accessibility criteria.