The problem is likely to be content rather than style. When that happens, editorial feedback is invaluable. Getting it may involve hiring an editor, reading a scene to a writer's group, showing the scene to a friend whose literary tastes are similar to yours, attending a workshop . . Obviously, Self Editing for Fiction Writers could be all the help some writers need to break into print. The simplest way to describe the benefit of getting your manuscript edited is that the book gets the editorial attention it deserves.
Rejection is a far more likely outcome for unedited manuscripts.
Second, we're selective about what we take on. But we won't recommend or agree to any further editorial work unless we see the potential for a publishable manuscript. This policy keeps really weak manuscripts from dragging down our percentage. There are a lot of good editors out there, many of them fellow drop-outs from mainstream publishing. Giving false hope to a writer whose material will never get published isn't just unethical, it's cruel.