kqr, there are a lot of usability problems that come from stretching columns across the screen. There's a thread talking around some of them here on this post: https://news.ycombinator.com/item?id=19621284
My thinking is that most programmers love information-dense displays. But designers have shown that empty space is vital to creating a truly usable design.
If a website used some minor CSS to add a bit more line-height and slightly-larger font than most browsers ship with, then fills 3840 pixels with wall-to-wall-text, you'll successfully achieve the most information-dense possible site, but utterly sacrifice readability.
Again, I don't think it's accidental that books don't use multiple columns of 66 characters in a landscape-style aspect ratio.
In true HN fashion, commenters are searching for a local maximum (use more of my big monitor) that defies how ordinary people interact with the written word. :)
