Recently, this question was deleted by the asker after I wrote an answer and added further clarification when the asker expressed some confusion about my answer. To be fair, I didn't have to think a lot about it, but it still took me a bit of effort to write everything up and add a reference for the statements I used.
I found the question reasonably interesting and from the comments of the asker, it seems to me that my answer has been at least somewhat helpful, so I don't think that deletion is the right reaction in this case. I'm really confused as to why the asker chose to delete the question.
Update: The Question is now undeleted by three 20k+ users.
Of course, everyone has the right to delete their question if no answer has been upvoted, but do you think that the deletion was justified/acceptable in this case?