My immediate answer would be it is because it eliminates a constraint. Thus placement is easier if alignment is not a constraint.
Do not see much of a value in this kind of question except for amusement of the interviewer and check if the person is wired differently.
I could see it being a fun kind of question to volley back and forth and maybe get a sense of how a candidate thinks. As an interviewee I could probably have some useful fun with it, but as an interviewer I wouldn't use it that way; there are other, more relevant, questions which could serve the same purpose just as well.