Is that actually the rationale, or are you guessing? It seems weak, if true, since:

- An article reporting X does not or can not necessarily always explain why X.

- Removing "Why" can (and does) destroy some titles, and submitters aren't always going to notice it was changed under their nose and fix it before submitting (or they will consciously trust the bad change, if they are not themselves an experienced reader of the language).

- Removing "why" doesn't seem to have any impact aside from saving a tiny bit of space and a tiny bit of annoyance for the small subset of people who are opinionated writers and dislike seeing the "why" trope in the cases when it is truly unnecessary.

It's not like we're talking about the "You won't believe why..." trope. Then I could understand.

But why does HN feel it's necessary to editorialize titles like that? My browsing experience isn't any better because HN decided to strip out the "why", and I've seen multiple situations in the past where the auto editing of titles here actually resulted in a title that made zero sense.

Lots of posts on HN state the fact "X" is happening and are searching for help to find the reason or just conveying a story. "Why" in the title tells people the author knows the reason and is going to explain it in the post.

"Why" only adds clarity. What is the advantage of removing it?