With the horizon right at the bottom of the frame, it make the image more about the outline of the city scape.
The horizon in the above image, doesn't feel bad but doesn't balance the buildings of the cityscape.
Here the placement of the horizon feels good but because of the cityscape, the proportions feel imbalanced.
With the previous to images, moving the horizon up to and above the middle of the frame, works if there was something to focus on in the lower portion of the frame but just looks bare.
This image seems to balance the horizon and the cityscape to make the horizon feel balanced and natural.