Well, I think there's a difference between being unable to find current contact information for an author and going ahead and recording a podfic, and choosing to record a fic over the author's objection.

I don't think people have or will frequently make that distinction. So, if we have a politeness standard that says, "You should ask the author," and one is unable to ask, the politeness standard then implies, "Too bad, so sad, all of that fic for which an author cannot be found is now unavailable for additional transformation." And I think that's a great loss.