If the title of a work (book, song, film, etc.) is a question (e.g. “Why Do Fools Fall in Love?”), should it always end with a question mark, or is it at the discretion of the artist? I’ve seen works that don’t have a question mark, and it seems wrong.
It’s up to the artist.
ETA: That’s why the sitcom of yore was entitled What’s Happenin’!!, with two exclamation points.
I understand that there’s a superstition against putting question marks in movie titles. That, I’m told , is why Who Framed Roger Rabbit has no question mark