Taylor Swift's wasting her time -- and more importantly the world's -- with stupid secret jabs at her rivals ... according to songwriting legend Diane Warren.
The rumor is Taylor packed her "Reputation" cover art with hidden messages targeting the likes of Kanye, Kim, Katy and probably an ex-bf or 2. Diane, whose rep as maybe the most prolific writer of pop hits speaks for itself ... hints Swift should be focusing on her music.
Diane, for one, clearly ain't interested in busting out a magnifying glass to delve deeper into Taylor's beefs with celebs. DW dismisses it as seriously "petty s**t" -- and also reminded us ... The Beatles did it better.
Paul is dead. Look it up.