The King was so famous that his manger, Col. Tom Parker, could demand that songwriters share songwriting credit with Elvis, even though he had nothing to do with the writing the songs. The songwriters would agree to this because they would make more royalty income sharing the credit with the King than they would if someone else recorded their tunes.
Elvis made more money at the writing game than 99.9% of the much more talented writers who struggle every day to pay rent and feed themselves on the meager or non-existent trickle of cash their words provide. This hardly seems fair, but I guess if a King wants something, he gets it.
There is a long history of writers, and other artists, getting screwed by shrewd business people. Creating art and selling it are two very different sets of skills, and artists are often naive, unaware and vulnerable for being financially exploited. In the case of writing for Elvis, however, it might be a stretch to call it exploitation for a songwriter to agree to share credit with Elvis – they still made out pretty good. Still, it highlights the role of economic power and business realities, and the role they have in the writer’s life.
I wonder if Elvis truly wanted to write songs, but was blocked and covering up his shame in a whorl of flashy jumpsuits, rhinestone shades, blue suede shoes and hip thrusts. Probably not. Why would he have ever bothered straining his brain for three verses and a chorus when there were scads of much more capable tunesmiths pounding at his door, who would essentially pay him for the privilege of delivering a fully-crafted song?
And all Elvis had to do was say “Thank you. Thank you vurrry much.”