The overall image quality isn't very good. It looks like these were taken with a smartphone. When the photos are enlarged to 100% or more they show compression artifacts. The photos are also oversaturated e.g. sky5, there are sizes of noise like in the seagull photo, etc.
So, in nutshell, the image quality isn't good enough for stock photos. (Not for Adobe anyway.)
Take a read of these links to get you started:
1) too many blown out and underexposed areas and overall blur
2) oversaturated, halos along many edges, underexposed shadows
3) leaning horizon, artifacts, blur, some birds are fuzzy blobs
4) noise, blur, artifacts. Zoom in to the sky in the upper left corner and you will see the artifacts clearly; had it not been rejected for tech issues, it would have earned an IP rejection due to the identifying marks on the boats
5) zoom in and look at the chest feathers on the bird - obvious colorful artifacts
All of the images are pretty when viewed at small size, but as soon as you start zooming in, the faults become evident.
I only looked at the first two. Underexposed shadows. Overexposed highlights. Halos between dark and bright areas.