Excellent skies, but an awful lot of distractions to this one. The birds are not really clear enough to add much to the picture, and the bright lights in the backround could be cloned out. The light poles and the electrical lines distract the eye as well.
The composition has a fair amount of potential and the colors are subtle and lovely. I suspect the c-index is a reflection of the business of the picture.
I agree with Rich on some of the issues. The birds are ok if the picture was Sharpened. The one on the far right is a distraction and could be cloned out.
First thing I noticed was the tilted horizon. It's a beautiful sky but could use a bit of contrast to give both water and sky a bit more impact. That would make everything darker so some positive Gamma would bring it back to the right brightness level. It looks good with or without the lights, but maybe a bit better as a pure silhouette. Also, cloning out the far tower as well as two or three of the most distracting uprights/chimney bits, cleans it up nicely and allows more concentration on the sunset and cloud formations.