I think that just because the challenge is something like "bubbles" you shouldn't just take a picture of some standard bubbles. The whole idea behind DPC is so one and get better and learn from their mistakes and other uses. If you notice the difference between your's and 1st it's the creativity, color, pop, the actual shot taken and the wow factor. Many of your critiques said that this image was boring and uninteresting, well I agree with them. It looks like you were just walking along a beach, looked down and was like Oh bubbles. ::snap:: Take your time and think about what you would like to use as a picture. Think about "what can I do that is really creative (or looks creative) that really stands out from everyone else"?
The reason your picture was given 183 F's or D's was because that is what you put out there. If you didn't study for the test you will fail. Don't take anything I said personally as I do not know you or any of your situations. I am only posting a comment to try and help you improve. Good luck
A simple image that is all about texture. Unfortunately it lacks the absolute clarity that an image of pure texture absolutely needs. I think part of the problem is the focus is slightly off, however the biggest thing that strikes me is the lighting. It looks as thought the image was take around midday, judging by the shadow of the bubbles. Midday usually produces uninspiring lighting as the shadows are very short and textures appear flat. This shot done again when the sun is much lower in the sky would produce a far more pleasing result I'm sure. With natural light it is all about timing.
My eye doesn't have a place to settle in the picture - no subject or central focal point. The sand sets a good textured but neutral/non-distracting background for the bubbles.