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.
The top of the subject in the forefront is not completely sharp. To see this it is necessary to zoom in at 100%. With more depth of field and targeting the center of the subject would include the top. Sometimes it means stepping a little away from the subject or zooming out a bit more. With a composition as this one having adequate depth of field to include at least two of the post in sharp view would have been more appealing, and that would ensure the main subject being in complete focus.