On the topic of authors being reluctant or resistant to sharing authorship credits,I wrote in a replay in a comment to the post,
I have shared the authorship credits of several stage shows where I was the initiator and the creator of 75-95% or more. There are two shows, a drama and a musical, that have made substantial money without my sharing in any of it—one because I added co-authors out of respect for their non-authorship contributions, the other for which I got no credit at all despite making the alterations that made the difference between the show being a hit and a flop. My wife thinks I’m a sap and a patsy. No, I think sharing credit liberally is the right thing to do, and that generosity should be the rule, not the exception. And I will continue to do unto others what they should have done unto me, even if the others usually don’t.
Here is a different personal perspective on the issue, in mermaidmary99’s Comment of the Day on the post, “The Betrayal And Ultimate Triumph Of Dorothy Seymour Wills”: