And the motivation: it's used as test inputs. Not sure I agree with completely destroying the readability of a perfectly readable file - but ok.
The motivation, as far as I see, was only that it "may be used."
But see the post of belorn where he argues that the error handling seems to be good.
Is the date on that accurate, did that happen in 2016? Kinda hurts the theory that they were trying to avoid Unix similarity.
https://github.com/coreutils/coreutils/commit/35217221c211f3...