Short lines are definitely good for prose (books makers have known this centuries), but I find that code is different. I tend to find code that has longer lines is much easier to read than code that rigidly adheres to (say) an 80 column length limit.

I think it's because I tend not to read code in order. I like to see the shape of it, look at just the beginning of the line to see what might be going on in that line and only looking at the whole line if it seems relevant to what I'm doing. Normally just seeing the first 20 or so characters (or pulling some keywords out from syntax highlighting) is enough to understand the broad strokes.