As the new behavious applies only to tty display, the only reason could be making the output more palatable to the user. Except, it is not -- the change might be somewhat excused when such a file name is a rare exception, but it makes things really hard to read when you have a mix of one-word and multi-word names.
Even worse case is when you have an apostrophe in a file name. That's a frequent case whenever file names are titles.
