As a copyeditor, I can completely relate to your observations. In my experience, the best writers are always the ones who worry the most — and who look forward to the editing process so they can learn for the next book. The weak writers bristle at every suggestion and are astounded that I’m “nitpicky” enough to have marked up their MS as much as I have. One author told me (after my first pass involved practically rewriting entire paragaphs at a time) that she was just burned out on working on the book anymore. My response was that if she didn’t care about her own book, she couldn’t expect anyone else to care more. I said it tactfully, but I was bristling. Her book (93k words) had 13k revisions and she was hoping for a movie deal once the big publishers finished fighting over who got to publish her . . . sigh.