It’s not that far from the truth, it’s just the thing they pick is what they saw on Fox News that morning.

Because long lines are bad for splits and/or vertical monitors. You don’t know the viewport the code will be read in, so keeping to a conservative width is helpful. If things wrap or require scrolling, that’s a lot worse for legibility, whereas having lines limited to 80 has minimal impact on legibility.

I personally format all comments to 80 (using vim’s gw command) and never touch LLMs.