When one considers that publications have people whose job it is to try to write link-baity titles, it doesn't always make sense for HN submissions to use the article's title.
Consider: it's not infrequent that writers loathe the cotton-candy bait their articles are given.
"Harry, smiling, had asked Professor Quirrell what level he played at, and Professor Quirrell, also smiling, had responded, One level higher than you."
As soon as the title enters the 'one weird trick' zone, which this title does, the link gets ignored. Though I did bother to read the hackernews comments about the story :).
When one considers that publications have people whose job it is to try to write link-baity titles, it doesn't always make sense for HN submissions to use the article's title.
Consider: it's not infrequent that writers loathe the cotton-candy bait their articles are given.