The message in this shot isn't really motivational, and that probably attracted some negative votes.
The crop of the shot, in oroutside of this specific challenge, is really not pleasing to the eye. There are shapes and ratios which we expect to see because they are found in the world around us and have been in use for thousands of years. Sticking to something of a classic rectangular 2:3 or 4:5 crop would probably work much better here.
I like the pic, I like the message, I just didnt like the fadeout around the edges (too much speckle), although maybe thats the look you were going for...