When I was working as an editor, the main reason I would have for rejecting submissions was "prose with arbitrary line breaks" 
When you don't know how much work goes into making a poem seem effortless, it's easy to assume that you can emulate it effortlessly. Unfortunately, those of us who do know how much work it is can almost always spot those who don't.

When you don't know how much work goes into making a poem seem effortless, it's easy to assume that you can emulate it effortlessly. Unfortunately, those of us who do know how much work it is can almost always spot those who don't.
It could be worse
