October Novel Prep Challenge

I am a little confused why a lot of the users seem so afraid about giving away information about their books. I see several posts about not wanting to give too much away, but why not?

As a writer, book lover, and sometimes critiquer of others' work, I might need to know some of that. Not that anyone specifically asked my help at this point, but it is also true for anyone else who could be giving help and feedback. I don't often click on links to go to the work because I have managed to give myself heaps of work to do.

Are you afraid we won't purchase a book you haven't written yet?

I do know that both agents and publishers look for the end spoiler information in query letters and synopsis submissions as a mark of professionalism of the writer. Even a rou draft ending might change before publication, and us knowing you from this challenge might be enough to get a lot of us to pick up the published book.

So, why keep so many secrets? I would like to understand.