Limiting the length of code lines is something I try to be good at, not because I think the next guy will have a VT100 terminal and needs a friendly piece of code, but because of basic readability.
When we read an ordinary text, e.g. in a book (you remember books, right?), there is usually quite few characters printed on each line. Here are a few from Douglas Coupland's JPod:
the door to see that all my new furniture was gone, and my
original furniture hadn't come back. Fuck. I phoned Greg,
but realized he was on Cathay Pacific 889, headed to Hong
Kong. I phoned Mom.
Notice how the text area is even narrower than that in this friendly blog?
This comes from a long tradition in printing, it isn't as if they couldn't have squeezed twice as many words in there, if the print was only smaller. But if the print was smaller, they'd probably make the book narrower as well.
It's far easier to read something when you don't have to move your eyes around too much from line to line. This is important to both slow and quick readers.
So, back to coders who make lines of 100+ characters:
What in friggin' Ruritania are you thinking? Not much, that's what.