please explain to me the reasons for removing this images? Reason - quality problems.
Both pictures are slightly underexposed and seem to show artefacts. As you did not upload the full-size pictures, it is difficult to go more in the detail.
Your second picture shows particles that should best get edited out.
As a second opinion, both of your pictures are too dark; maybe you intended to give a dark and moody feel, but overall I think it is too dark for stock use. The customer can darken the image if they feel a need to.
So, in terms of quality, one issue - the main one - would be exposure problems. The foreground is rather dark in both pictures. The exposure should be balanced out a bit more.