I wouldn’t go so far as to say he isn’t serious or unreliable. I do understand Ellison’s perspective. He’s big on writers’ creative control and the issue of intellectual property, and why he was vigorously defending Travers.
You don’t happen to have a link to the New Yorker piece ?
Link
http://www.newyorker.com/archive/2005/12/19/051219fa_fact1
My guesss is this article from 2005 had a lot to do with their idea of making this movie.