I have a few short stories in a folder on my computer called Dead Stories. There's an old novel in a drawer somewhere too. None of these materialized into publishable works -- at least not yet. I wouldn't be surprised to learn this is the case for other authors.

As for perfecting a work before sending it out, there's a lot of comptetion for fewer slots in magazines and on bookshelves. An author better perfect a work before submitting it to a publisher. Otherwise, the author is making the decision to reject the work an easy one.

I think both writers and publishers have their own roles. Both must complement each other. Perfection can be subjective especially when you talk about the concept and the creativity of the storyline. Moreover, the publisher's role, more than proofreading, should be on how to implement strategies on how the book will be introduced to the entire market, on how to catch attention.