A rejection comment that I see a lot on the forums I frequent is that someone's writing isn't "special" enough to be published. Technically it may be perfect but it lacks the zing that grabs the agent/editor's lapels and keeps him glued to the sofa.
I think it highlights the problem we have as writers. Usually criticism on peer review forums deals with the nuts and bolts of writing; technical skill which is easy to pinpoint and put a name to. Rules and spelling, grammar etc. Of course you need all that, just as you need a feel for structure, dialogue, scene-setting, characterisation. But having learned all those things you then need the passion to put it all together. Like a chef creating a dish from all the various ingredients, it is passion and energy that lifts it above the ordinary. But it's elusive. You can't find it in the grammar or the structure or any other components. It's there, driving the writing forward, keeping them reading.
There's a kind of channelling that happens when you concentrate so hard you forget yourself or time and it just flows. Has anyone else experienced that? Almost as if this story isn't coming from you at all but somewhere else. That is where this drive comes from, I believe. It's an unconscious thing, so perhaps that's why it makes us slightly uncomfortable. It involves forgetting ourselves and just creating.