To my mind, anyone who doesn't get this is probably a lost cause either way as they likely would be painful for a publisher to deal with once the edits started

To my mind, anyone who doesn't get this is probably a lost cause either way as they likely would be painful for a publisher to deal with once the edits started coming back, and I'm just talking the first round where the editor gives suggestions/etc, not even the final copy edits where final grammatical errors are cleaned up. The trick is learn to find two sets of readers. One who just love reading and can articulate what they like and what is lacking in a story (they really wanted this plot thread to finish but it kind of died, that sort of thing) then a group to help catch grammar and punctuations mistakes. After that if you think it's worth the cost (aka you think it has a shot of doing well) paying the ~1k+ for a professional editing service to have one last go over it is a good idea since they do that sort of thing for a living. Now if I could just find my two sets of readers once I finish the second draft of my novel...