It's been for several years now that we have high resolution monitors, and 4K (for programmers!) is upon us. I think it's time to part with ancient 80-character default width for source code.
On my 1920px width monitor I code comfortably at 100-characters width in two editors side-by-side, although the font is a bit small at 10. On a 3840x2160, I expect to turn the monitor in portrait mode (it's gonna be too wide for web browsing at 3840, 1920px already breaking lots of sites!) and squeeze two code windows side-by-side with at least 120 characters usable width. This is a 50% increase over the standard 80-column width for editors !
Moving to 120 characters code width seems to have a lot of advantages; we can use longer variable names, we have space for longer expressions, e.g. lambda functions or generators; and the commit messages (I look at you, git) and comments will not be awkwardly split in a quarter of the screen.
Question is: how do we start moving everybody to use 120-characters default width for their code ?
I also don't think being able to fit a "lot of action" on each line is an advantage at all because code like that is hard to follow, debug and refactor. If you instead split it up over multiple lines it becomes easy to see what the common parts are and refactor them into new functions.
There is also a lot of people with poor eyesight who uses large fonts and would have to horizontal scroll (big pita) 120 char wide lines.