The debugging argument is a joke - who doesn't have some sort of soft wrap option on their editor? what about people who don't write one-line css but tab nested classes (such as the writer of the article)?
No, it helps people who like one line. You leave soft wrap off normally, and you see your lines the way you intend. If a line extends off the end of the screen, and you don't want to scroll to see the rest, turn on soft wrap to see, then turn it off again.
