How would an author feel about their characters being changed when they are dramatized for the stage or screen?

Mystery writer Agatha Christie addressed this situation during a presentation on the online lecture service, BBC Maestro, in a dramatization. In a discussion of character, a simulated Christie purportedly says,

… “And there is, of course, Ariadne Oliver: an author character I created, who mysteriously shares many of my thoughts on writing and the world!

“I remember that in Mrs McGinty’s Dead I had Mrs Oliver reflect on her experiences with another writer who wished to dramatise one of her works for the stage, but then proceeded to change the characters and story for some unfathomable reason.

“So far it’s pure agony,” Mrs Oliver told Poirot. “Why I ever let myself in for it I don’t know. My books bring me in quite enough money. That is to say the bloodsuckers take most of it, and if I made more, they’d take more, so I don’t overstrain myself. But you’ve no idea of the agony of having your characters taken and made to say things that they never would have said, and do things that they never would have done. And if you protest, all they say is that it’s ‘good theatre’.”

“I will allow you to decide whether that is really Mrs Oliver speaking, or myself. But I do remember when a stage dramatist made Poirot a younger man with a hint of a love interest … That‘s certainly not my Poirot!”

Luke Skywalker got hosed.