My photo was rejected. Why?

Adobe said:

Thanks for giving us the chance to consider your image. Unfortunately, during our review we found that it features excessive post-processing and/or noise, so we can't accept it into our collection.

Excessive artifacts/noise can be caused by low light, bad camera settings, strong compression or excessive post-production.

If it was due to post production effects, know that our customers typically prefer to add their own special effects, filters or black-and-white conversions to fit the needs of their projects, so adding these effects in advance drastically reduces the market for your image.

This was focus stacked with Zerene Stacker, but so were many other images that they accepted.  Is it background noise?  Would doing some post-production noise reduction get it through with another attempt?  Is something else wrong?

Many thanks in advance.