Is photography using depth of field usually not accepted? This was rejected due to "image out of focus", where the background rings are that way by design. Are macro images using 2.8 or less commonly rejected as well? This one was 1.8
Rejection isn't automatic; I suspect it has something to do with the subject matter. I've had nature shots with beautiful bokeh get denied, but this one of mine just got approved. Can't get much thinner DoF than this.