While she might have her own bad rap about somethings, I truly believe she approaches every role as an "artist". Now, with that being said, she doesn't accept every role...big or little.
Plus, looking at the film version, it would of been a challenge for Patti, or any one, not to say how bad it was.
I'm guessing Patti wanted to remember EVITA as it was on stage and not spoil it with a mediocre, lackluster film.
"She couldn't act scared on a New York City subway at three in the morning."- A review of Sarah Brightman for "The Phantom of the Opera"