No serious literary critic or academically recognized literary scholar EVER took McKuen seriously as a "poet."
On the other hand, many serious artists, art historians, critics, curators, etc., have high respect and serious regard for Jackson Pollack and Andy Warhol. It's not unusual for regular folks like us to dislike weird art, I suppose, but I still don't think it's quite fair, or even logical, to plug those two names into this exercise.
I like Stringsinger's proposition that songwriting is a higher calling than poetry. I agree; I enjoy and admire thousands of songs, and couldn't care less about most poetry (especially modern/contemporary).